One other hypothesis I’ll throw out there is that part of the problem is that general education is seen as a phase that one goes through and then is done with. If you have stuff you want to study in an academic way, you better cover it while you’re at school. I went to undergrad for 5 years and still never had time for subjects like philosophy as much as I may have enjoyed it. The breath of human ideas is too vast to cover in the time we give for it.