What's the source of sluggish career advancement for Linux system administrators?

I know a lot of Linux sysadmins who work 60, 70, or more hours per week who rarely see the light of day and even more, rarely see a bonus or hear a "thank you." It's no wonder there's massive burnout and job turnover, but now it's time to get to the heart of the problem and find out why. Career mobility and advancement are two big reasons and I suspect that others feel that same pain. Let's find out the source of the career advancement question.

I know that not everyone wants to progress into management, but there needs to be something to look forward to in your career other than all-nighters and weekend on-call. Career advancement has to be a topic of conversation for system administrators and employers.