It may be a stereotype but if you walk into most comic book/anime stores and look around at the people in them, the vast majority will match up to the stereotype.
Must depend on the store, or area perhaps.
My local comic shop happens to be a music store that started selling comics when digital downloads started crippling their sales. As it is, the wall where the new comic books are displayed are next to the used CD racks. You see a guy (or girl) go down that aisle, and you think you can predict what they're going to buy, by comparing them to these ingrained stereotypes. And yet, I'm surprised (and sometimes shocked) almost every week, when someone I "just know" is going to the used CDs actually starts picking up the latest offerings from Marvel, DC, Image, etc.
Do I see some of these stereotypes there? Sure. But not as often as I see someone you wouldn't assume is a "comic book nerd" if you saw them walking down the street.
How often do you really have to move 100 MB or 2.5 GB of files around?
Every time I buy a newer, bigger hard drive so I can store more porn without deleting the old stuff?
Heard that the next Space Shuttle is supposed to carry several Guernsey cows? It's gonna be the herd shot 'round the world.