Calling this a "glitch" is disingenuous. It (is/was) an open secret for my entire undergrad. There were plenty of professors who would encourage students on 8-hour appointments to work 20~30 hours/wk with no overtime pay. Professors control access to valuable research positions and grad school applications so if you wanted to have a career in academia there wasn't anything you could do about it.
This comment is greatly exaggerated. I've never heard of 20-30h for 8h TAs, and even milder overworking (like 10 instead of 8) gets resolved when it's brought to people's attention. The professors I know actually do care about offloading work and not overworking people beyond their hours. I don't know how many such extreme experience you might've had personally, but the description doesn't seem to paint an accurate picture of what's been happening overall.
