I once read an interesting article comparing a college education to high heeled shoes.

High heeled shoes were once a utilitarian device: They made it easier to keep a solid grip on the stirrups when riding a horse. As footwear, the feature embodies a tradeoff that's only practical for a particular class of people: Riding a horse is easier, at the expense of making walking a bit less practical. But since this class of people happened to be wealthy, and it's common for folks to want to mimic the habits of those wealthier than themselves, eventually a fashion for high-heeled shoes developed among non-equestrian classes. That development also divorced the shoes from their practical roots, which allowed fashion to take over and push the shoes to even more impractical extremes, which is where we get modern incarnations such as women's pumps. To some extent, the only real purpose served by such shoes is to signal to others that your day-to-day life doesn't involve doing anything that would render them too impractical, and therefore you're of a higher social status than anyone who doesn't wear them.

Higher education seems to be starting down a similar path. It used to be that it was a thing for the upper classes, who were expected for various reasons to have a well-rounded liberal arts education. Because of this it became desirable in part because wealthy people do it. Nowadays that seems to be a major driving force. How else can you explain why a time-consuming and expensive BA is still considered more desirable than one of the trades, many of which offer comparable or even better income prospects?

I disagree. If you look at non-technical white collar jobs, they all involve mainly analytical and persuasive writing. It doesn't really matter if you're writing essays picking apart Foucalt, or writing a memorandum explaining why the company should buy this kind of server versus this other kind of server. It's the same skills.