A lot of it is dependent on what is essentially "blood magic" but I don't think there's anything innately Vampire about that.
I want to preface this with me not actually being against the idea.Because I don't want to throw away an IRL year of RP about being cured, people being happy that I'm cured, and people being willing to engage with me because I've cured, simply because a huge chunk of my tether's group utility is locked behind a subrace that will automatically CHAOS DUNK all that RP directly into a trashcan.
That said, to play devil's advocate, the complaint largely seems to stem from the stigma and reputation of the class and the associated Dominion rather than the actual mechanics of the class. While making Praenomen into a Blood Mage class and divorcing vampirism wouldn't be a far or even terrible stretch of lore, I have to wonder if it's really worth the time and resources?
If being outside the Dominion doesn't really do anything mechanically and the main repercussions are roleplay... does that warrant a class rework? It'd definitely be cool but the mood surrounding the class feels very... "flavor of the month"y to me for a lack of a better term. It wasn't even that long ago when vampires were every where. What's suddenly changed?