Agreed. It's kind of stupid to look at someone's username and say, "Oh, well, your name is (or at least looks like it may be) a reference to X pop culture entertainment, therefore you suck!" One, it cuts OP off from getting to know potentially awesome people. Two, it just makes OP look like a shallow dick. I, for one, don't care that my name is dorky and fantarded--it's fun and flows nicely. I know plenty of other people who have fandom-related handles who otherwise have their shit totally together and just happen to like geeking over something.

Besides, most people outside of whatever fandom someone's username is taken from just don't get the reference(s), so...yeah. =/