I think role-playing in an MMORPG is just stupid. I mean all the power to you and all that, but no thanks.
...but I think this change is awesome and wish FFXI had it. Two situations where bad names irk me.
1) MMORPGs are not only about the gameplay and online community, but also immersing your self in the game and world. It's like an adventure, exploring new areas and such. When you finally reach some great new location and then the first thing you see is "CockSuckFucker121 says "FUK U ALL, UR GAYZ"", it really does throw all the immersion out the window for me. I mean I don't want anyone roleplaying with me, I just don't want to see something that doesn't fit the setting.
2) In most cases, people with said names are usually bad players. You can tell their in it for the "fun" only, and won't put the effort or seriousness the games sometimes require. I mean you compare CockSuckFucker121 to someone named Aldian Thrall (or some crazy fantasy name), and I guarantee you that Aldian guy will put the extra effort into his character. The other guy most likely won't be. It's a huge blackmark for that "fun name" guy to have. Like me personally, I wouldn't party with him just on the assumption he won't be as good as someone with some fantasy name.