Earlier quoted context omitted.
This a thousand times. > And while they are the primary workhorses of research, there are large swathes of their graduate student careers where they are not particularly (or often negatively) productive. Um, hello. This happens in industry as well. It's called training, learning, whatever. It's an investment on the part of the company in the future of its workforce. Why should academia expect to only pay employees wh…
You have a point, but graduate students are actually paid a salary, unlike what you suggested.
There are a lot of problems, though. Your funding isn't guaranteed; you can be basically kicked out of the program (because very few people can afford to self-fund) for reasons that have nothing to do with you or your performance, and if this happens in your 4th or 5th year, you're fucked.
The other ugly fact is that even if you're not paying tuition, your advisor is. This means there's less money to send you to conferences or fund his lab, and it means he's under tighter financial constraints than he really should be. Your advisor gets his budget docked $80,000, and only $20,000 goes to you (the rest, to tuition). That's a bit ridiculous, especially because you're no longer taking many classes or using university resources except to do work on their behalf. There's no good reason you can't be paid $50,000 and your advisor has $30,000 more to fund his lab.