Introverted people focused on a specific subject, such as pure-math research, tend to go where society deems it beneficial for them to go. So you are good at math, but you need to eat. Where does society think it's useful for a mathematician to apply his or her skills? Well, our society gives the NSA substantial funding, which it devotes in part to hiring mathematicians. The rest of society does not fund pure-math research much at all.
And yet somehow society is surprised that many pure mathematicians end up working for the NSA. Maybe if you cheap bastards were willing to pay for math research through a different mechanism, the mathematicians would work somewhere else.
If the common man weren't so chickenshit that they keep voting the same folks into office and refusing to hold their government accountable, maybe we wouldn't have to deal with the alphabet soup agencies making ready use of society's intellectually-talented castoffs.
I'm good at cunnilingus, and yet I need to eat, too! What to do, what do do...
Do you know the story by Thoreau in "Walden" about the basket weaving indian? Also, while I agree that something like math research is ultimately benefitting all, this doesn't really apply when it's done for spooks, since those tend to sit on it. So if math is all you're good at, and if you positively can't wait tables or learn anything else, so you can use your math skills for non-profit and the commons or teaching math on the side, then you might be screwed. And if you just go work for the NSA, you're not exactly beating a path out of that situation for future mathematicians either.
Same reason that, if you think gentrification is problematic, yelling "die yuppie scum!" at the poor schmucks trying to find a decent apartment in an overpriced area isn't either an effective or an intellectually sound strategy. Instead, one ought to look at the structural forces producing gentrification, i.e. the developers and capital movements.
An article on that subject: http://jacobinmag.com/2013/05/the-fucking-hipster-show/