You mean that Bloodlines 2 betrays fans of Bloodlines 1 by removing the ability to create your own character? I can agree with that view. Although I am unsure about how many people would actually consider it to be a deal-breaker and for how many it would be "It sucks, but it's still Bloodlines, right?" had the game been on the level they'd expect of it.
It would be very difficult to compile all the reasons why people enjoyed Bloodlines. We can ascertain the aspects in which the game excel, and where the game fails utterly. The game's aesthetic and ambience are perfect, the play with lights and shadows is excellent. The combat is mediocre to terrible. But that's different from asking people what they particularly enjoyed about the game. It can range from 'oh, I like urban fantasy and there aren't a lot of RPGs like that' (which is my case) to 'oh, I liked drinking mortals dead with celerity' (also my case).
What I do think is that the change from a silent protagonist to a voiced, well defined Elder called Phyre who used to work in Cairo is more than just an aesthetic change. It has a number of practical and subconscious implications that pile up, and I'm seeing them in the community's complaints and reservations.
One complaint that took me by surprise is the idea that the four available clans are all samey. I'd have thought that the inclusion of Banu Haqim novel enough to dispel that. At first I chalked it up to the lack of Malkavian, the standout clan from Bloodlines. Or even the lack of Nosferatu, the clan with significantly less impact but whose sewer adventures have people talking anyways. Now I think the issue runs deeper.
When you get down to it Ventrue, Brujah, Tremere and Banu Haqim should all be radically different perspectives in any story. Arguably the three former clans were not radically different in Bloodlines. The C&C between having an early Ventrue apartment or a late Tremere apartment is nice but not such a big deal. However, like I said before, it's easy to take ownership of a silent protagonist even if you can't customize their appearance. That's the subconscious effect: the player might feel as though they are picking between flavors of Phyre, rather than what type of vampire they are in the night.
Then there's the practical effect. There
could be more radical changes between being an Haqim Elder or a Ventrue Elder from the middle east. But with a fully voiced protagonist using a FO4/Mass Effect esque dialogue, the odds are there won't be. You'll have a choice of 'reminding them who you are', and they'll say that 'you were called the slayer'. The limitations imposed on the writing team by a fully voiced protagonist and their headmate are likely to bolster the feeling of which flavor of Commander Shepard you're picking. This devalues all cosmetic and actual C&C they can afford to create.
That said, I am willing to bet that this game will flop because of lower production values only. The corollary is that it could have survived through the lifeline of a jank immune Bloodlines fanbase. But I'll go farther and say that the odds are the aesthetic choices of the game will kill that lifeline, while the jank will kill the out-of-fanbase appeal of the game.