That’s probably true, but as a staff software engineer myself, I can tell you, that more often than not, it’s because they don’t know how to say no and they’re terrible at managing their own time. Engineers need to understand that the higher you climb, the smarter you have to be about your time, not just work more. In that case the promotion and salary bump doesn’t make any sense. They could have just gotten a second job and would have still made more money.