Feminists come in many different varieties. It seems to me, half of the feminists who know about Bayonetta support it as a "female empowerment" type of game while others are disgusted at how sexualized it is. It's best not to generalize that most feminists hate Bayonetta.
To be fair, a lot of feminists and women alike find it offensive that even though the game is a satire of hyper-sexualize females in video games, the material is still offensive and sexist/portrays women as objects. To some feminists, sexism is a very serious matter and jokes are never taken lightly. Jokes are seen as encouraging the stereotype and encouraging sexist behavior (which is true; an example is, it desensitize us from realizing and recognizing the actual problem with sexism) and I don't blame them at all for disliking Bayonetta.
On a side note, Bayonetta is my favorite slice'n'dice/beat-them-up action game and I find it to be much more enjoyable than (not recent) DmC games and God of War. My only gripe to people complaining about the game is when others have not actually played it and claim it's terrible because it's "soft-core porn".
I didn't literally mean a hate mob. Yes, you're right. They are disapprovals and people generalizing that feminists are "men-haters" which isn't true. I'd have to suspect half of the disapprovals are from people with inefficient knowledge about feminism. You know what I mean.
I can't really elaborate on something that I don't 100% agree with, can I? I don't think she was an object at all, but I sure as hell heard it elsewhere from friends and online. I guess if you'd like to know more, you can search online?