[Straw]

I'd much rather have a mentally ill person with treatment flying the plane than without!

You don't get to choose "no mental illness" because of the bad incentives of hiding them!

[account42]

Those don't have to be the only two options. You can also criminalize hiding your mental illness as a pilot while incentivizing self-reporting via sufficiently generous disability insurance.

[Straw]

If you criminalize hiding your mental illness, you can be sure that people will hide it! Even if the alternative has some money attached.