The many, many things that I like about MIT, and the fact that I am so glad that I went there, are chronicled here and elsewhere. So I'll bite, with the "dislikes" thing:
- Discipline snobbery (i.e. "My major is more hardcore than your major!"). The people who engage in it are a minority (and who they are varies, since for many people it's a defense mechanism when they're taking their major's most brutal classes), but they're a loud minority.
- Too much emphasis on being hardcore. To quote a friend who got his bachelor's, master's, and PhD from MIT, "I was really hardcore as a freshman. Where 'hardcore' means that you were dumb, but survived." It can turn into a masochism contest very quickly, with people depriving themselves of food and sleep, taking more classes than they can reasonably handle (I did this, with near-catastrophic results), or even going into majors that they don't really care about (see my first point) in order to prove to everyone how tough they are.
- It may have more student freedom than most campuses (a plus), but a common perception is that this is dying little by little (a minus), and would be dying faster if there weren't students working hard to preserve it, and a subset of sympathetic admins and faculty. <political digression> In some ways it parallels the US under the Bush administration, and Krueger was our 9/11. </political digression> *I* don't actually believe that traditional MIT student culture/freedom is dying, but it gets more and more difficult to uphold it.