He brings up a lot of good points, especially that academic careers demand an eccentric combination of activities comfortable for both introverts and extroverts (studying alone for long periods vs. standing in front of large numbers of people to explain what you've found -- not to mention the obligatory conference schmoozing and job interviews).
But as someone who's always been introverted (having taken the meyers-briggs probably a dozen times over the years and always having scored something beginning with "i") I still have to take issue with his confusion of introversion with a kind of anxiety about social situations. Introversion and extroversion are about where you get your energy, from being alone or from being social. It's not the same as being shy.
For example, discussing the problems faced by introverted graduate students:
Meanwhile, most graduate students are teaching for the first time, and the introverts are constantly worried about how their reticence will damage their credibility in the classroom: Will my hands tremble, will my voice quaver, will I be able to smile naturally? Will they challenge my authority?
Social anxiety is no more a necessary marker of introversion than extroversion, though perhaps it is a trait more common in introverts because of a lack of practice in social situations. I am no more nervous in front of a class of students than I am sitting in a pink bathrobe at my computer at two in the afternoon with a beer in my hand. I was the very first time, but it had nothing to do with my introversion and everything to do with the fact that it was something new (the getting up in front of class, not the pink bathrobe). It's like going on a first date. If you're not a little nervous, you're in the minority.
That's because being comfortable in front of people isn't anything to do with extroversion. It's about being comfortable in your own skin, being unafraid of being foolish, and being aware that you are your own worst critic (Unless you're in a job interview. Then you're looking right at your worst critic who for some reason you weren't expecting to be there, but who totally is right there. Where's my scotch?)
Now if we were talking about being exhausted after half an hour of rubbing shoulders with (even pleasant) eminent scholars at Kalamazoo, or after speaking for an hour to recalcitrant students who really couldn't care less whether it's "could care less" or "couldn't care less", then I'd be right with you. That's exhausting stuff. I used to wish I smoked so I could take quiet outdoor breaks every hour -- now I just take mental health breaks to "get some fresh air".
But I don't get shaky in front of a crowd, and I'm not made nervous by meeting new people. It's just like going scuba diving: the faster you jump in, the more you get done before you need to come up for air.
And that's my two cents for the afternoon.