He didn't say most; he said many. He also said introversion is common: One of the researchers he spoke to, Susan Cain, puts the estimate closer to 50%. Of course, this depends on when you think someone is mostly introverted and when you think someone is both significantly introverted and significantly extroverted (and when you think someone is mostly extroverted, but the article doesn't address that). The reason he says he wants to pay attention to introversion is because its complementary trait, extroversion, is:If most people tend to fall in the middle of a spectrum (according to a normal distribution) why is all the attention on the extreme cases of exclusive introversion and extroversion?
By some estimates, 30% of all people fall on the introvert end of the temperament spectrum
the unstated norm, and against that norm introverts stand out as seemingly problematic.
Perhaps we should be using this effort to increase awareness of the moderate position between the two extremes, not elevating introverts at the expense of extroverts. As a spectrum, it's unlikely that most people lie at the far extremes. Continuing the discussion of introverts vs. extroverts just perpetuates this false dichotomy.