I guess it all comes down to whether you consider a degree to be education or training. You could make the same argument as to why schools teach things like history, English lit, RE rather than more practical leaning subjects. We're always hearing some pressure group or other saying how 'x' should be added to the curriculum such as nutrition or financial management skills, would they be more useful than learning about crime and punishment through the ages, the rise of Communist China or pulling apart the meaning of a book written 500 years ago in language barely recogniseable as English? There are lots of companies with graduate schemes that just want a degree at 2:1 or higher and don't care what the subject is, all they want is someone who has shown they can apply themselves and have an aptitude to learn so that they can take onboard the training that will be given. Many of these are in big, blue-chip companies and can lead to very highly paid jobs. Often those jobs will be something a kid of 16 or 17 having to choose the path that will define the rest of their life has never even heard of let alone have considered for a career.
On the flip side 'vocational' type degrees aren't always great for the future careers. I've work with graduates in my line of work that have all the theoretical knowledge but if a solution requires something that isn't by the book they just can't get their heads around it. This is probably not helped by having been taught by people with no real world work experience and using software packages etc. that are years out of date.