That's why they were the "liberal" arts - they were studied by free people, as opposed to vocational things, which were studied by slaves. To extend that to today, if you need the money from a job, don't study the liberal arts. If you can afford to not work for a living, then the liberal arts are appropriate for you.

Now, in a non-slave-based society, we think that all citizens should know something of the liberal arts (which I in fact support, and wish our education system was better at providing). But a degree? Only if you don't need the money.