It may also be because university education used to be for those with a great interest in science, and I guess for some reasonably intelligent upper class folks with nothing better to do. The first group had the motivation, the second group the habit and education to express themselves well. Today it is for those who want to get a good job. The education for a job majority lowers the standards for everyone.

Btw I'm a middle class guy who did it mostly for job prospects and such, so...