I always felt the same way while I was in grad school. The fact that my tuition was covered by working as either a teaching assistant or as a research assistant on a grant, AND that I actually got a paycheck that was mostly-enough to survive on, was something that I was very grateful for.
It was not something one could live on long-term (no chance to save money whatsoever, could never buy a home or decent car, etc). But, I wasn't starving and I wasn't taking on debt.
At the same time, it is a sacrifice. Most of my friends the same age were making "real" money, buying homes, going on nice vacations, saving for retirement, etc. So, I get extra irritated and defensive when I hear people who have no idea what they're talking about repeat conspiracy theories about science and academia. If I wanted to be a rich scam artist, I'm pretty sure there were better options than a science PhD...
Opportunity cost is real, and it's probably one reason why fewer US students (who can work in the US without worrying about visa or related issues) seem to be going into graduate programs. Graduate indenture is an unappealing prospect, even more so when you are looking at being worse off than your parents' generation.
Tuition coverage for grad students is a way for universities to take money from grants and pay it to themselves. (And for undergrads they often limit the amount that external scholarships can reduce the expected student and parental contribution, in order to pocket as much money as possible.)
It's still important to realize that grad students are cheap labor for research (e.g. from NSF's perspective if they are the funding agency) and teaching purposes (e.g. from the university's perspective.)
It was not something one could live on long-term (no chance to save money whatsoever, could never buy a home or decent car, etc). But, I wasn't starving and I wasn't taking on debt.
At the same time, it is a sacrifice. Most of my friends the same age were making "real" money, buying homes, going on nice vacations, saving for retirement, etc. So, I get extra irritated and defensive when I hear people who have no idea what they're talking about repeat conspiracy theories about science and academia. If I wanted to be a rich scam artist, I'm pretty sure there were better options than a science PhD...