A lot of people go for that and they are hard core fans of particular show or comic books. There are always a lot of celebrities there signing autographs and participating in panels. It might be fun, but the crowd factor just turns me off!
I don't see the essence in taking photos with celebrities, although some people might have vanity for it, but I don't think that's for me anyway
I think it's stupid too, I've never done it and I've met several celebrities. With one had a nice 45 minute conversation, didn't ask for autograph or pictures. Some people seem to think celebrities are "special" I guess, there just people like you and me who worked hard and got lucky in their profession.