Bear with me; I'm going at this one sideways.
At one time, I was "officially" supervised by someone high up the corporate ladder, so I didn't really have much contact with him. At review time, he gathered reports about my work from the project managers who I actually worked for. This worked out fine because he was a terrific manager (and geologist, although at this point in his career, he'd risen too high to actually do technical stuff) and I really respected his advice.
During the review, he'd ask about my medium and long-range career goals. In my first review, I'd only been working there a couple of months and my goal was pretty much to do interesting stuff in consulting, because I didn't really have a clue. Later on, I admitted that I was planning on going to grad school. My supervisor thought I would really limit myself if I didn't get an advanced degree, but he also said, "I have more people trying to come in here with coursework towards x degree. It doesn't mean shit unless you finish a thesis and get those letters after your name."
My company would pay for my tuition (up to some dollar amount) if I kept working full time, if I only took 1 class at a time (i.e. I'd be studying and working forever), if I could work out how to do fieldwork at the same time, etc etc. It is so easy to get derailed when you're working full time, probably doing fieldwork so you're working more than full time, and coming home exhausted only to do homework. And then life happens, and your advisor sort of forgets about you because you're not in his/her face all the time, and before you know it, you spend years and years trying to just finish the damn thing. I couldn't do that.
So I worked my ass off, and took all the overtime I could, and saved my pennies, and then I skedaddled. As a STEM grad student, I had a decided advantage over some other folks because all the schools I applied to would support me with TAs/RAs/scholarships, so that in theory I wouldn't have to dip into savings while in grad school. But for me, 2 years of (relative) poverty is worth it to get the degree and then go back into the workforce a better scientist.