First off, it is definately NOT taboo, just look at most of this thread.
Nobody forced anyone to join any of these groups, they are merely a group of people and a name associated with regions in FIRST. They don't necissarily have to be "representative" of the region, but as of now, NERDs definately have representated the North East. The shirt is seen in dozens of photos, they have a video podcast, a website, etc etc etc. Thus is the power of publicity. You don't have to cheer for NERDs, you can certainly cheer for your Northeast defense (although the bit about it being better than Midwest offense is quite wrong, imho
), nobody would be mad at you.
Regional pride and regional rivalries are a healthy growth in FIRST, and are common in almost any competition. These groups act as another form of networking and can only help. I realise you may not like them, and that you're entitled to your opinion, but I ask you, who and how do they hurt?
And finally, you may be trying to say that robotics isn't just for nerds, but maybe they're trying to say "It's cool to be a nerd!"