You've hinted at your experience without providing details (even the school or the type of graduate program). I obviously can't comment on your situation because I know nothing about it. I am literally assuming nothing about your experience.
I do know other Harvard grads (both undergraduate and grad programs) and have some insight into their situations. They don't have "massive, insurmountable debt." Anecdata abound.
I vigorously agree with your last point.
As a result the people I know from the time who went on to graduate degrees all had free rides (except the MFAs, who I admit are a mystery to me, and the people who went back for MBAs later).
All that I said I do agree we shouldn't be burdening our youth with crippling student debt. But the idea that our culture comes from our humanities departments seems a little absurd and not supported by evidence.
It's interesting that so many replies function on these kind of assumptions when I am telling HN my literal experience at an Ivy League postgraduate program. I received two of the available three fellowships one could compete for. They covered less than 5% of tuition overall. Six figures of debt was the norm for my program.
Now of course, as you said, no one is forced to get a degree in humanities or what have you, but my point is that if you make expertise in these fields contingent on massive, insurmountable debt, you impoverish the culture.