Defense contractors set their own payscales but also compete on price. I know software engineers right now earning north of 150K. Also, overtime is paid and billed in defense. Thus, if you do work overtime, your defense contractor wants to bill it and you get paid for it. My first year out of school I made nearly 100K on a 67K salary because of billed overtime. This was in 2003.

There is also the fact that finding ways to get more ads in front of people is not inherently motivating for some engineers when compared to building space systems or solving other interesting problems like deconflicting telescope laser alignment with satellite orbits.