I really hate the implication that being an introvert means you are not as good at interviews or HR type networking.
I am an introvert. I have a huge professional network. How? Simply by being nice to people and caring to build a network! And I know plenty of extroverts who have a much smaller network than me because they tend to burn bridges when they leave companies, because being an extrovert doesn't keep you from being kind of a dick.
And as hackers we are often stubborn and passionate about objective truth and I think these HR/networking problems have nothing to do with introversion.
I think introversion is being used as an excuse. And I suspect a lot of introverts are either not introverts at all, or have entirely separate issues in addition to being introverts.
Certainly a lot of what I read about introversion has nothing to do with it, but is clearly about social anxiety.
It's a "pain point" precisely because there's no reason a somewhat 'introverted' individual should be organizationally penalized for their personality traits when they 'bring the goods' regardless (or even in excess of requirements).
That does not happen! The only way I can imagine that happening is if you are an introvert who happens to be a professional party host, or maybe sales. But introverted personality traits do not get you punished professionally if you do any kind of intellectual work like programming! What ever punishment you're seeing, I'm guessing it's due to social issues entirely apart form introversion.