I think its also a circumstance of looking at the employment picture to see who is in need of a job.
If you can get someone with a higher education level than a lower one why not choose the higher one, they may be smarter and perform better.
Back in the 1950's to 1990's you could easily get a job with just a high school diploma or less, now that there are so many people coming into the
employment market such as new immigrants, companies are thinking lets get the best educated ones we can, it might only help are company in
the long run.
The other aspect to realize is that the world has evolved into a more technical working society where higher education is a real necessity,
which in turn requires people with a better education than in the past.