^ I guess it's for the same reason we've got so much litigation and people employed in litigation. If people just used their sense we wouldn't have those trying to sue each other right and left and need tons of lawyers, but it creates jobs in the litigation culture we have, which is supposed to make us 'safer' (because not many people are using their sense, I suppose). Making people have to get a piece of paper to get a job means more people are employed in teaching them in order to get the jobs they want.
I've been to uni before and believe me there are people who get the paper at the end that are still unfit to the do the job they are 'qualified' for, and there are people without formal schooling who are clever enough to do it. I asked myself the same question, and now I see further education is being commercialised - universities are charging students to be educated just to be able to compete in an increasingly selective job market. The original point of university is being lost, which was to provide a place of learning to produce the most qualified society needs... engineers, medical specialists, scientists, teachers, mathematicians etc. Now they're more interested in milking people's desire for a 'good job', but it's the governments that have encouraged it all. It's part of a policy of making public institutions function like businesses instead of public services, and trying to create jobs out of nowhere for people to do.