The Affini are good. They, on a fundamental, deep-seated level, want what's best for you, and if turning you into a pet isn't what's best for you, they wouldn't do it. And they're almost always right.
On a purely Wattsonian level, that "almost" qualifier is the thing I'd be worried about if I was a HDG human (well, that and without access to Doylist-level knowledge I'd have some pretty serious doubts about the truth of the rest of that statement too). Sure, Affini may have benevolent intentions, but they're going to mess up sometimes, because they're not omniscient, and because they don't seem obviously much smarter than humans (most of them would have a lot more experience than any human because of their long lifespans, but experience/knowledge is only one facet of intelligence).
Somebody else objected to my position on I think basically left-skepticism grounds in the tags, and the left-skepticism argument against it is the one I find most compelling.
On a more meta/Doylist level I guess my true objection is that I'm adjacent to the kind of person the setting is designed to cater to but not actually that kind of person, and, uh...
I remember once reading a post on this site saying that calling your lover "Daddy" has different vibes when men do it in a gay context vs. when women do it in a heterosexual context. I don't remember it super-well, but the argument was something like the straight "Daddy" is about pure power but the gay "Daddy" has more of an idea of the "Daddy" as an aspirational figure and a mentor and somebody you might become like some day. It didn't say this, but the subtext I got from it was, like, that kind of relationship has different dynamics when it's between people of the same gender because then you don't have a whole cultural complex of gender bullshit encouraging you to think of your lover as a fundamentally and innately different type of person and encouraging you to conceptualize this kind of relationship in gross bio-essentialist complimentarian "natural role" terms, in a gay context that kind of hierarchy is more easily recognized as the conditional and contingent and provisional thing it actually is.
I feel like the difference between HDG and what I'm into parallels this. Like, yeah, a lot of HDG stuff reads to me as D/s for people for whom safety is hot who'd enjoy having a kind and indulgent psuedo-parental figure who they get to have some kind of sexual intimacy with, same hat, that is also one of the few D/s-adjacent dynamics that's appealing to me and it is very appealing to me. But it would be really off-putting to me have this offered to me on the terms of "you're going to get this as part of a bio-essentialist racial hierarchy in which your dom(me) is assumed to have a right to control you derived from their innately morally superior character that is derived from their biology, your subordinate status relative to your dom(me) is permanent and unchangeable (is there such a thing as floret manumission?), and this is going to come bundled with severe violations of your consent, autonomy, and bodily integrity, extreme contempt for your intellect, and radical disregard of your stated preferences." I would like having a mentor who is wiser than me and a helper who is stronger and more competent than me, I don't want a controller, and, uh... Well, there's a point occasionally made that a lot of kink scenarios are horror scenarios to people who don't have the kink, I wouldn't go so far as to say HDG is a horror setting to me, but it's definitely something that provokes mixed feelings when I read or contemplate it.
I wonder if this has something to do with the differences between the cis autistic experience and the trans experience? A lot of trans people seem to have a feeling of "I wish somebody had ignored my stated preferences to satisfy my real preferences, and been empowered to do that over my most strenuous objections" or at least find that very relatable. If you're cis and autistic (as I suspect I am) I guess you're likely to mostly just associate people ignoring your stated preferences with stuff like being pressured to eat foods you don't like and wear clothes with textures you don't like.
Like, there's a bit in Dog Of War (just read it, well, skimmed it anyway!) where Princess chooses an internet username that's a Dune reference and Camilla decides that Dune isn't quite ideologically kosher and forces her to change it, and all I could think of reading that was how infuriated I'd be if somebody pulled that shit on me and how scared I'd be if an authority figure with the kind of power over me that Camilla had over Princess at that point demonstrated that kind of interest in intrusively micro-policing my self-expression.
Aside: the point about Affini not seemingly obviously much smarter than humans made me think an interesting scenario would be Dog of War but Princess is a Blindsight vampire (in this scenario turns out they were a thing in the HDG universe too and the Accord tried Jurassic Park'ing up a few of them for approximately the same reasons Blindsight humans did). It'd be interesting to see an Affini try to deal with a person who actually has a pretty big advantage over them in raw brainpower (though, as Kirk said about Khan in Star Trek, compared to them it would be intelligent but inexperienced), who'd likely be relatively apathetic to a lot of the attractions the Compact offers, and who would definitely be in the "potential danger to others" category but would probably not like the idea of being a floret at all (vampire social instincts would be wired for low-trust relationships, the idea of anybody having the kind of power over them an Affini has over their floret would probably be extremely viscerally terrifying to an adult Blampire). And I think you could write a Blampire that's survived in human society in a way that's actually kind of on-brand for an HDG protagonist.
I suppose this is part of the reason stories in the setting consistently load the bases by emphasizing just how horrific life under future space capitalism is, and just how miserable it makes everyone. Like, I cannot stress this enough, the Terran accord fucking sucks.
It kind of backfires for me, the Accord sucks so anviliciously it makes me very aware of how I'm being emotionally manipulated and it feels like the logical objections to/opponents of domestication are being strawmanned. Like, I would really like to see one of those captive humans raise the obvious relatively sympathetic objection to the Affini's face value self-presentation ("You're enslavers! We beat assholes like you on our own planet before we went to the stars and we'll give you the hardest fight we can before you drag us back to that old night! Destroy my mind if you want, the cause of freedom has many martyrs and I would be proud to take a place besides the likes of John Brown!") instead of just spouting strawman-y right-wing nationalist cliches. Even if it gets brushed off as them not understanding how the Compact's society and florethood works at all and being misinformed by Accord propaganda, I'd respect that more than just setting up "rargh gargle my balls I have indomitable Terran warrior spirit I am a fashoid space racist!" as an obviously deliberately unsympathetic strawman for the Affini to knock down. Not that I necessarily object to the latter existing, but it'd be nice to see more acknowledgment that people might have sympathetic and principled reasons to react to the alien invaders who are doing something that looks a lot like an imperialist war of conquest against your people and have something that sounds a lot like slavery with horror and defiance. As I said earlier in a different post, you could even play this as the Accord's rank and file soldiers and spacers being tragically misled and propagandized by their right-wing authoritarian leaders, but, like, if so how much more of a visceral stab in the heart would it be if instead of memetic Best Korea style blatant lies played for humor about how silly they are they're given an at face value plausible and consistent with the Affini's own words narrative that they're facing basically leafy Draka and they live out something pretty similar to this/this but then after the war the ones who lived through that and managed to survive it find out they were given a very deceptive impression of the stakes of the conflict, a lie that is half a truth is all the bitterest of lies etc. (and, like, I actually think that might be pretty good for making the Affini sympathetic too, I definitely get some feels imagining, like, the Accord's equivalent of the Battle of the Line and it cuts away to the Affini and they are doing their equivalent of crying their eyes out about how scared those poor humans must be and how brave they're being and how awful the whole thing is).
And the Accord sucking so bad makes it easier to read the Affini's deal as a Jacob's bargain/the equivalent of getting a dog to swallow a poison pill by wrapping it in meat.
There's no war
Except for the wars of conquest the Affini wage against any sapient aliens they meet who resist their domination! Yes, I know the Affini don't consider their domestication campaigns wars and that totally has verisimilitude as a way they'd think of it, but my reaction to reading that exchange in Dog Of War was thinking I'd have liked if Princess said something like "It sure felt like a war to me and the rest of the crew of the Valiant, and I think our experience of it counts for something."
One last thing. I reject the idea that the terran accord would have done better with the more advanced technology of the Affini. Technology is a tool, and a tool's use is downstream from the society that builds it.
I think I just disagree with you about the relationship of technology and society. I think the Marxists are more-or-less right that culture and social order is mostly downstream from material conditions and the power balances that emerge from them (I mean, I think it's also downstream from biology and that might be significant when comparing the trajectory of human civilization to those of alien civilizations, but I find a bio-essentialist pessimist reading of "humanity will never build socialism unless a species more biologically predisposed to it than us forces it on us at gunpoint, thankfully the Affini are there to be and do exactly that" pretty distasteful).
P.s. if you're looking for noblebright opposition, consider "No Gods, No Masters", which takes a long philosophical look at how human communists would handle the Affini. It's quite something.
I've thought of taking a look at it but TBH am not sure I want to do so because it sounds like lots of what makes me uncomfortable with the setting turned up to maximum.