The stereotype has existed for a long time and I'm glad some pride is finally being associated with such interests which earn the label. And as the pride swelled, so did the marketing, posers, and exploitation. I see it as a growing pain. The stereotype is being accepted and even glorified. There will always be the many empty individuals who latch on to some label and try as hard as they can to be something, be anything, just so they won't be nothing. Maybe next time you see a person "posing" as a nerd try to be nice. strike up a conversation about something you like and ask them about what they like. If it appears they are "faking" you don't need to verbally assault them and stick up your nose at the "inferior brand of person." Maybe even have the courage and confidence to try and cut through this label he or she wrapped themselves in and ask about their family, their "real" life. He or she probably is looking to fit in or for a friend, even if they aren't consciously aware of it.
I would say that the exploitation comes from a basic skimming of "nerd culture." 'Nerdism' is not so much about taking a subject and learning about it as profusely and intensely as you can, the main stream culture sees 'nerdism' as a vapid interest in sci fi, fantasy, math, and comics—or something along those lines. Currently, it is more a fashion than anything—with the glasses and the plaid. I'm not going to be pulling rank on peoples' nerd levels either, that would be as repudiating as the culture the 'nerds' have always moved away from. What bothers me is the caricature-like pastiche it all has become. Taking this show as an example and another that comes to mind is The Big Bang Theory, where 'nerds' are all follow the same quirky oddball stereotype that loves to speak in movie quotes and references.