A university president makes a case against cowardice

Those giant university endowments are partially used to allow those who couldn't afford it but otherwise have shown they have what the university is looking for in students to attend for significantly/entirely reduced costs. Meanwhile, the most visible billionaires are using their money to try to buy elections so they can dismantle the government for personal gain while oftentimes employing people with such low wages that they depend on the government to be able to afford such luxuries as eating three meals a day. It's pretty easy to see why the large parts of the public find one acceptable and the other less acceptable.

Endowments are typically restricted funds (imposed by the fund provider) and can't be used (unless the restrictions are removed) to be used for general operating budget.

Harvard generally uses the interest on the fund principal to pay for things and it was a massive internal controversy when folks proposed drawing down the (absolutely enormous) principal as payment for capital expenditures (among other controversies).

Everyone can afford it if given a loan. If the job you get after can't afford to pay back the loan, it's time to look for another career, and for the schools to be on the hook for the miss, not the taxpayer.

And yes you are right acceptability, because polls show that the government bailing out students making poor career choices and schools paying for bloated staff is definitely not acceptable to the majority of Americans.