I guess I'm in the minority here, but I don't personally mind it...if the style used has some actual personality.
On Mizahar, I acknowledge that it's clearly a bit weird to use drawn characters because everybody else uses photos, unless, as in the case of Pycons, it's not feasible. While I think a lot of visual personality can be added in a drawn character, the disparity in avatars between a photo and a drawn character does create a mental disconnect for me, as other people have mentioned, when picturing the two characters together in a thread. However, maybe because I'm also an anime fan, I wouldn't necessarily avoid threading with someone because of their avatar, but the style they chose to represent themselves with may make me take a look at their CS and past posts with a more skeptical eye.
I would also like to expand the distinction between drawn characters, anime style, and what I like to think of as the caricature of anime style, which is what I think a lot of people here are thinking of. Below are three images, the first two of which are actually avatars I've used on other sites:

They are all drawn avatars, but in widely different styles:
The first is more of a painting, and I probably wouldn't think twice if it was used here on Mizahar alongside photos. It's got detail, personality, and obviously took some skill to create.
The second and third are anime-style. The second, I get that a lot of people wouldn't like at all, but I think it has more detail and personality than something like the third. It would still be weird to use it here, but I would have more of a problem with an avatar having fluorescent eyes rather than the simple fact that it's drawn in anime style.
The third is what I think everyone thinks of when they think of anime-style. It's generic, it's boring, and the only thing it says about the character is, 'OMG SO KAWAIIII'. There's not much that can be said about it.
Not sure what to say in conclusion, other than that's just my thoughts and I can honestly see why there's such dislike for anime avatars. I just don't personally feel that strongly about it.
On Mizahar, I acknowledge that it's clearly a bit weird to use drawn characters because everybody else uses photos, unless, as in the case of Pycons, it's not feasible. While I think a lot of visual personality can be added in a drawn character, the disparity in avatars between a photo and a drawn character does create a mental disconnect for me, as other people have mentioned, when picturing the two characters together in a thread. However, maybe because I'm also an anime fan, I wouldn't necessarily avoid threading with someone because of their avatar, but the style they chose to represent themselves with may make me take a look at their CS and past posts with a more skeptical eye.
I would also like to expand the distinction between drawn characters, anime style, and what I like to think of as the caricature of anime style, which is what I think a lot of people here are thinking of. Below are three images, the first two of which are actually avatars I've used on other sites:
They are all drawn avatars, but in widely different styles:
The first is more of a painting, and I probably wouldn't think twice if it was used here on Mizahar alongside photos. It's got detail, personality, and obviously took some skill to create.
The second and third are anime-style. The second, I get that a lot of people wouldn't like at all, but I think it has more detail and personality than something like the third. It would still be weird to use it here, but I would have more of a problem with an avatar having fluorescent eyes rather than the simple fact that it's drawn in anime style.
The third is what I think everyone thinks of when they think of anime-style. It's generic, it's boring, and the only thing it says about the character is, 'OMG SO KAWAIIII'. There's not much that can be said about it.
Not sure what to say in conclusion, other than that's just my thoughts and I can honestly see why there's such dislike for anime avatars. I just don't personally feel that strongly about it.