[grepthisab]

You kind of buried the lede in your last paragraph:

This is largely due to MIT and similar schools having massive endowments from which they can draw for Financial Aid; there are cheaper schools, certainly, but they have coffers that are less deep (referring to private schools), meaning students end up having to take more debt.

It is reality that expensive schools cause the massive student loan debt problem, but expensiveness isn't totally buried in sticker price but total cost of attendance. Schools like HYSM don't saddle attendees with as much debt despite their high sticker price perhaps because of endowments.