I had sort of hoped Keyleth would have matured and grown past her anger at the Matron over the past 33 years but I suppose it's in character that she hasn't fully dealt with her grief yet. And the Vorb probably isn't helping her issues either. It just sucks because I think a lot of the fandom take Vox Machina's grief fueled blame and fully accept it as fact when the reality is that Vax's situation is almost entirely his own responsibility. The only other person with any remote culpability is Percy. And even Percy is only really to blame for accidentally Killing Vex, not for Vax's choices. But even if you want to hold Percy accountable for Vax's choice in the tomb as well, that still doesn't make him responsible for Vax's death. Vax could have lived a long full life as the Matron's Champion, as shown by the Delightful Purvan Suul and his companion Galdric.
Vax was a borderline suicidal, self-sacrificing character from day one. He always threw himself into danger headfirst regardless of the cost to himself. Between Percy accidentally setting off the trap creating the circumstances for Vax trading himself to the matron during Vex's resurrection, all the way up to Vax CHOSING to come back as a revenant after being disintegrated in order to help defeat Vecna, the choices have always been his. Especially him, fate touched as he is. Ultimately, Vecna killed Vax and Vax killed Vax. I think it's easier to blame the Matron than to be angry with Vax for being who he was.
The Matron maintains the balance of life and death. She accepted Vax's offers both times, do you think she should have refused? The first refusal would have meant Vex's death, and the second refusal would have meant Vax possibly just staying dead after being disintegrated, and not being there to fight against Vecna, which was truly an all hands on deck situation. There was no time to fuck around with a resurrection ritual that might not even work, the whole world was in danger. One life, a life that was already lost, is a small price to pay to save the world. I'm pretty sure Vax would agree with me!
Frankly, Vox Machina were super lucky and privileged to have so many successful resurrections between them. I think they got a little spoilt and entitled about it honestly. Most people have never even met someone who's been resurrected before, they did it like 20 times! Vax was disintegrated, he chose to come back as a revenant to fight Vecna, protect the world, and help his family. An opportunity he was only given due to his allegiance to the Matron. She gave Vox Machina and Vax extra time together and a chance to help save the world.
For those of you shouting "what about true resurrection!?! I hear you, and Matt said it's complicated and didn't elaborate lol. Personally, I think the Matron has quite the special a barrier of entry to true resurrection, if the spell even works at all in Exandria. I think they touched on it briefly in Calamity but I've forgotten. I can only imagine what insane ritual Matt concocted years ago that he's had plenty of time to work on since. Part of the Matron's whole thing is that everyone must eventually go into death, sure they can avoid it for a while, so some resurrection is fine (the DC gets higher every time), but eventually enough is enough and it's time to go. Hence why necromancers and liches are her enemies.
At any rate, I'm really proud of Keyleth for going to therapy and I hope she goes back when all of this moon business is over because she still needs it and that turtle lady in the frog seemed great lol.