>Then why are you doing it?

Planning on getting out before the next cycle of crazy hours.

But to answer the question - various reasons. It facilitated a relocation to Europe. Rapid career progression to managerial level. Control over what projects I want to do. Multiple rounds of overseas assignments. Minimal supervision. Exposure to new things in a notoriously secretive industry. Pay is decent too, but that's not really a motivation for charging hard.

>is the job market too tight to get a less cruel job

No I can walk into a job with equal pay and far less stress tomorrow. It would kill progression & personal development though. I figure I can always coast later if need be.