Probably has something to do with the fact that gamers don't exactly spawn all the frequently, and when they do, they want to name their kids after video game characters.
If I ever have a boy, his middle name will be Revan (KotOR). My wife is currently pregnant with twin girls and I'm pushing for Aerith and Celes, probably as middle names. I think Aerith might just have a chance...
As for video game names being more traumatic and lead to teasing down the road...I'm not really seeing it. By the time your kid is in school, how many of his peers are going to know Aerith as a video game character? Not many (and the ones who will would most likely be geeks-in-training). Kids are going to find something to tease just about every other kid about, sooner or later (some kids anyways), so what difference does it really make? If it's not the name, it'll be something about your appearance, if it's not that, it'll be how you're dressed or how you talk. It's a crappy reality, but it is reality...rude, crappy people spawn rude, often crappier people.