I'd hazard a guess that the general population is more readily accessible to study, just by virtue of being numerous.

And in many cases the study data already exists, and the aeromedical folks just have to parse it.

The benefit of doing a pilot-specific study is that it would account accurately for our specific circumstances, health benefits of socioeconomic status and lifestyle, and also any potential detrimental affects from job environment, circadian disruption, etc.

If the government is going to set boundaries on our livelihood, they owe us an accurate number, not just something that evolved over time. Might even be a lower number, in which case you can move up and FIRE even faster.