Another Geek Fallacy?

It's not quite a social fallacy, but it's one that I've seen often enough. Some fan sees something he doesn't like in an upcoming movie, and taking inspiration from by the old Trek fan campaign that kept the original series on TV for a season, he believes that the power of fans opinions can make or break a major production. I've seen it time and time again, in fan reactions to films ranging from Star Trek, to Star Wars, to Lord of the Rings: it usually involves some statement about how no true fan will go to see the movie, and they will get all of their friends to boycott it as well.

In fact, they usually resemble statements like this one I saw today:

Paramount should want there to be a RPG based on the new movie, not because some game company pays them a lot of money, but because it will help them out in the long run. Roleplayers are a disproportionate portion of the traditional Star Trek fan-base. There's a lot of Trekkies who hate the very idea of a new movie and can't imagine anything worthwhile coming out of revisiting the license. They're not just going to boycott the movie, they're going to flood the fora and convince all their friends to skip it to.

Oddly enough, I've never seen one of these threats of mass action have an effect. But these fans never seem to stop believing that they have a power of numbers that just doesn't exist.