Some of them are snobs. Some of them are silent. Some of them are actually very kind and friendly! Others are none of these, but more that they have their style of speaking and humor, which is exaggerated by the legions of "fanboys," if you will.
I don't care for them and I don't care about them. If they won't bother responding to my comments, then they're not worth my time. Of course, there ARE a few popular artists who'll occasionally answer comments that aren't all like "lol that's so awesome you're so awesome I wanna be like you lol " For example, some artists, like :icondrayokstart:, etc, will answer a comment if there is a relevant question or comment to be answered. ^^ I like that. But if they don't answer at all, they're not worth my time.
Some of them I feel like they are snobs because they ramble about little things concerning themselves in their journals yet won't reply to questions that I ask them. But then there are some who are so busy that they can't answer every comment made.