Sorry, it was unfair of me to send that to you without proper context since you might not be aware of these issues. Irredeemable media refers to any thing with a creator or content that is harmful and/or bigoted. Of course every piece of media has problems, but irredeemable media is when those problems cannot be ignored and are an indicator of someone's beliefs.
For example, Harry Potter is irredeemable media because every one knows that JK Rowling is a transphobe, but some other piece of media like Twilight would not be considered irredeemable because even though Stephanie Meyer has done some bad things, they are not as widely talked about, so someone who posts about Twilight on here isn't completely likely to be a bigot, but a Harry Potter blogger would. Also, I know the "to be cringe is to be free" people like your blog, but a lot of the time, what is considered cringey on here is actually based on what is irredeemable. No progressive person or reputable blogger genuinely makes fun of My Little Pony fans any more, however plenty make fun of Hazbin Hotel fans and the such because that content is irredeemable and shows someone's beliefs. So usually, a piece of media being considered embarassing to like on here usually indicates that it is irredeemable.
As for why the other pieces of media are irredeemable, Hazbin Hotel is made by a woman who has many well-documented accusations of bigotry against her and has drawn zoophilia art, not to mention how her work leans into stereotypes about gay people (having a gay man character be a sex addict, a lesbian be named after the female body part Vagina, etc.) or at least that's what I've heard. Attack on Titan is created by a known fascist and many illusions are made to nazi imagery and nationalism in the anime. Captive Prince has a racist premise that sexualizes slavery and non-con.
People can tell you that liking irredeemable media doesn't say something about who they are, but that's fundamentally false. If someone is uncaring enough to still post openly about these types of media, it's clear they don't care enough about not supporting bigotry. Yes, even if they don't give money to the creators, because they are still willingly exposing themselves to bigoted or harmful content and enjoying it.
The previous ask was not meant to be accusatory. Rather it was meant as a concerned question. Believe it or not, there are still some users on here who indulge in these pieces of content, a few of which hide behind the excuse of being part of a minority (Black, trans, whatever) or simply deny how bad their media consumption is to escape accountability. I wouldn't want you associating with those types of people and have that ruin your reliability on this website.
Hopefully this ask has educated you more on these issues and you'll be able to spot irredeemable media in the future and block it out.