So unless you have done Science, Maths, Medicine, or Law, your degrees are useless?
With all due respect, you'll find a lot of the people at top 25/30 universities, who think academia is everything, when it really is not. That's why you find degrees like History and English floating all around the high scale employment areas. In fact, History is the most common degree amongst FTSE 100 directors, so it obviously got them on a path to somewhere. Also, History is not simply going to library, finding a book and quoting from it. At degree level, you have to have a solid passion for History to imagine things in the time your studying, analyse different factors etc.
People are suited to all kinds of different subjects. You'll probably also find that Arts and Humanities graduates can do the general number crunching and AS level Maths that are required for most jobs, as well as possessing the communication, writing, social and analytical skills that firms want. I would bet that the most Science and Maths graduates would struggle to write a report, have good presentation skills as well as social skills, because for those subjects your mind literally works like a factory; there's only one answer, which means you don't really create, and you could stick your head in a book and do 1000 questions and you'll eventually get there.
As for Law, well a lot of people do it and don't actually get very far. Doing History or something keeps your options open for a conversion degree, because Law is quite streamlined for, just Law. I've been told employers sometimes question Law graduates who apply for non-law graduate positions because it gives an indication that they're indecisive.