You know, most of the time I get a chuckle out of creative naming, but after the first few seconds, I realize that this person is introducing him or herself to the world at large in a very juvenile way. Power to em if they like to crack jokes, but this is an on-going joke that they live with every day, and which preceeds them everywhere they go. While it's not so much about immersion, it just reminds me that I'm surrounded by people who probably spend a good chunk of their day picking their noses and thinking up fart jokes.

As far as interpersonal interaction goes, I think there's a bigger issue. I remember the Good Ole' Days of UO, where there was no way to turn off PvP. Griefers would do ANYTHING to get you to attack them, or to frustrate people who just wanted to play. Because people can hide behind their accounts, there's less incentive to actually behave themselves, and if someone had a bad day at work (or is just an ass in general), there's nothing stopping them from taking their bad day out on people they don't know or will never meet. That's entirely unacceptable.