Sure, but market signalling in a profession which takes years of education and training can lead to the same issues.

And this article shows that market signalling is largely not working in this case (because people do not approach education on a rational market basis).

Definitely, but private colleges exist, so you can always learn it on your own dime. It's just the government tuition free systems that have that restriction. Similar thing here in Australia.

But they're not nearly as big as the dangers of predatory "for-profit" education.

And I'm fairly sure I've never heard anyone say "Oh crap - we've run out of lawyers."