I don't think that quite holds up. Sure, lots of people want to do it, but lots of people want to be professional athletes or surgeons or [insert prestigious job here] as well. Similarly, this kind of work is extremely demanding, and very critical - the consequences of incompetent traffic controllers would be disastrous - so there's still a low supply of people who actually are a right fit for the job. In a sane job market that should still give these traffic controllers some bargaining power.

Then again, I guess braythwayt's comment[0] is real-world proof that we're not really dealing with a sane job market, so I'm clearly missing something crucial in my line of thought here.

[0] https://news.ycombinator.com/item?id=24346728