You do have several trends and phenomena converging here. There's the fact that folks in their 20s usually don't make much money, education or no education, because employers value experience. A combination of education and experience helps boost increasingly in your 30s, 40s, and 50s.

There's the recession.

And then there are the trends in education that the article discusses. Much more information in this Pew Report:

http://pewsocialtrends.org/files/2011/05/Is-College-Worth-It.pdf