Any reputable MMO has safeguards in place to prevent or discourage most of such behavior. You're going to get stupidity and childishness, sure, but those are pretty easy to avoid, especially in games with a more niche audience (i.e. not WoW).
Besides, who talks in "l1eet" in 2011? :confused:
While safeguards do exist, they are not actively enforced as that would take far too many manpower hours. The onus is on the playerbase to report such behavior and unfortunately, most people find the 3-5 seconds it takes to file a report to be too much of a hassle.
I do agree that niche games have better communities (that's why I joined this forum, after all), but TES has grown very quickly over the past decade to the point where an MMO would probably be a very popular and mainstream affair.
1337 is 4 suxxorz.