I don't think it's money. I think it's requirements and training pipeline restraints. The system is predicated on being able to throw bodies at the problem, but there is a distinct lack of qualified individuals to back that up. Personally, I didn't realize ATC as a possible career path until I was 36-- imagine my surprise when I found that I had already aged out.

Who would want to work that job once they find out what the day-to-day is like? I had an intern who looked at that out of the Air Force but he found out what you get paid and what the expectations are for the job and he figured he'd try his luck on something easier and better-paying like life-preserving medical devices. On a related note, why do you think nobody who you'd actually want teaching public school actually teaches public school in the US?