The point is that most of HN identifies themselves - on the Myers-Briggs scale anyway - as introverts. The test labels me an extrovert, yet I do not see these artificial, and frankly invented, differences between all of us.
I also mentioned that this sort of broad labeling is divisive - and I certainly feel this way. I've been labeled as a Myers-Brigg extrovert, and now I have the rest of HN to thank for assuming that I'm a brash, shoot-first-ask-questions-later sort of guy.