That's in fact why some universities patent their research stuff in the first place, to ensure nobody else can. They'll then make it a policy to take 0€ in licensing fees, but this precludes anybody else from starting to lock the tech behind money.

Source: My uni back in the days had a few dozen patents for exactly this reason, too.

A patent also ensures no one else can patent it. If they make it affordable and available they are protected from someone else patenting it and then “profitmaxxing” because they have legal recourse to prevent that.

Of course now it is up to them to do that…

Public universities receive funding from a multitude of sources. Research is typically funded by grants, which may come from state or federal sources, but they can also come from alumni, fundraising, or charitable trusts.

Regardless, patents are a necessary part of invention. As others have pointed out, without a patent, what’s to stop some other entity from coming along and (for example) using your hard work to make themselves rich? I’d wager if it were your invention/discovery, you’d want protections too.

There are some entities out there that would easily abuse patents. But I find it hard to believe a public university would be one of them.