You're very optimistic. I suspect there are
tons of people who can not get through law school
or get an art history degree!
I've spent quite a chunk of my life around people who are somewhere on the lower half of the intelligence curve. I grew up in poor neighborhoods, and attended a pentecostal church for much of my life (which at least over here contains the full spectrum of 'classes', but skews working class).
Lots of these people just cannot handle the level of abstraction (or whatever the thing is they need) to obtain even the easiest of college degrees.
On the other hand, I also learned that 'smart' is a very multi-dimensional thing and from their perspective 'academic me' is a complete idiot in so many ways. I'm just saying that the particular skills needed for (most of?) college are skills that a lot of people don't have.