> Especially, don't work your ass off expecting to be rewarded. It never happens.
I think this might be an over-generalization and that this is might only hold true for people who are farther along in their careers. I'm currently in year six of mine and I've been given a lot of great projects and early promotions (with subsequent pay jumps) from having been in the minority of people on a team that is working their ass off. These returns have, however, diminished with time.
If I had to hazard a guess I think this is probably because a more junior engineer working their ass off can show quick and obvious improvements to the quality of your work and time management skills, which start off as near excrement and iterate to "ok" over time.