Sure, there are some people who are invested in the cause, they're not social events only. But a large number of those showing up are not, they're there because their friends are, because it's an event and something to do, and because they want to belong to a tribe, and tribal outings are the thing to do when you want to be a part of the tribe.
Most of them don't want that more than they want to stay dry though, so bad weather usually translates into smaller events.
Most of them don't want that more than they want to stay dry though, so bad weather usually translates into smaller events.