It seems like people still have a sort of misconception about Computer Science as a lone wolf art. Some people just don't realize that computer scientists are as social and as friendly as anyone else, but they have a passion, and that passion often can't be shared with others, because others don't understand it. It's the same way with any other artist. People can appreciate the art that an artist renders to some degree, but they probably won't appreciate the real devotion to every aspect of their craft that the artist possesses. Computer scientists are artists. And we love to get together with other people who can share and understand our passion as well.
A wonderful example of this is the OpenBSD hackathon, as described in this article written by J. C. Roberts.