i don't even think it has to do with CM being the "in" thing to do. i think some people are just looking for some way to buck the system in any way they can, and so they go out and do this. either that or they're like me and are just looking to meet new people (why i went to a bunch of them in boston. new people i met: 0).
while i appreciate the good intentions, CM in berkeley really is just a solution looking for a problem.