> ATC isn't even the worst offender. Law enforcement and prison guards can pull 100+ hours a week on a regular basis. This is how prison guards can pull $400k/year.

There's definitely elements of that - but part of that is that many pensions are based on the two highest earning years of your career, so it's "common" among cops when they are planning to retire to spend two years working every possible piece of OT available, to maximize their pension income.