Aren't all stereotypes true to some extent? That being said - some are more true than others. The campus is not overflowing with queer students, though they do make up a valuable and vocal part of the community; everyone is not a high hippie - we have some articulate conservative students here, along with a significant range of more moderate students as well. We undoubtedly stray toward the liberal side, but I don't think it would be at all fair to brand everyone here as a "hippie," whatever you may mean by that.
As far as elitist snobs go - I think we are to a degree. The school is a successful one, but I sometimes wonder if that has gone to its head - it's hard for ACTC students (those attending the associated sister colleges in the area) to sign up for our classes, while it remains relatively easy for us to get into their classes. Our campus orgs rarely interact with those of other campuses, which is a little silly considering how small we are - why not bring in fresh faces? I don't know if this is directly because of an elitist attitude, but I know it ends up looking that way to more than a few.
Diversity is a huge issue in my opinion. The campus has a laid back attitude about it, accepting that there are differences and different people, but there is little effort put into understanding those by any but a small (but significant!) minority of usually colored students. The school's administration makes little effort to reconcile international students (a large part of our student body) with the smaller population of domestic students of color - each has much to gain from the other, but that potential has yet to be reached.
If you're quirky, you will fit in, no matter what your quirk. I came to this school with three other students from my high school and the only thing we had in common was that we were all politically liberal; each of us has found a niche and are thriving. Be warned though - some of the quirk sometimes manifests as awkwardness.
Mac is one of the very few places I know that gives you real and abundant opportunities to impact your surroundings. Just go to the Civic Engagement Center and you find so many opportunities for volunteer work in the cities. Mac alums tend to have gone to work for some socially beneficial cause - yes, even the econ majors.
Econ and the hard sciences are often joked about, but that doesn't mean they aren't valued. The econ department alone has three different student organizations created around it, and the hard science kids find good resources at their disposal and a genuinely caring faculty that makes themselves readily available.