Having a piece of paper with a prestigious name on it, really means nothing. One can graduate with the bare minimums and get the paper.
Getting a job AND KEEPING IT, require more than a framed piece of paper.
Often times, people are NOT HIRED before they even walk in the door.
In todays world of electronic resumes and social media, companies often weed people out by their online presence.
The ones that do get interviewed can disqualify themselves just by the clothes they wear or how they wear them.
Body language also plays a part in how an employer perceives someone.
I've got a buddy, when he talks, he often sounds like Eeyore. When he doesn't sound like that, he's usually angry about something.
Nobody is going to hire someone with a black cloud over their head. And if they do get hired, chances are they'll be the first ones cut loose when things slow down.
My buddy has had that problem. Repeatedly.
Soooo...though many might make claims like this article, of over educated but under employed, they are really looking at a much bigger picture through a very small hole.