A separate problem which compounds this is that European universities have been switching to the Anglo-American Bachelor/Master system from the previous diploma system, and many employers consider these new titles to be worthless.
People do science and engineering for the love of it, sure, but these kinds of people don't forget that someday they'll need to support themselves. It's not only the skills but the down-to-earth attitude that makes these people such prized commodities in the job market.
The kind of person who does Art History in the first place is the kind of person whose family has the money to support them to essentially pursue their hobby full-time for 4 years.
College isn't about getting jobs. That's how it's used now, and that sorta sucks. College is about learning things you couldn't learn better elsewhere. So they're going to learn art history because they really want to know about art history, not because they're trying to make shitloads of money.
I also dislike the snarky tone you take when referring to "people without useful skills", but that's secondary to the main argument.
(Also, the humanities and social science majors I know are just as down-to-earth and hard working as the science students. They have tremendous skills, albeit different ones; solving tricky differential equations isn't everything in the world.
The problem is not that these graduates are unskilled, but rather that the whole economy has taken a nosedive, and the kinds of jobs they used to take, which required their intellectual skills, just don't exist in their previous numbers. For example, as described in the article, media and advertising are being crushed.)