I don't think that's quite what DD said. If the purpose of going to school is to prepare you for work in that field, then extraneous classes outside that field can be seen as a waste of time. I disagree of course, since I think any class you take can help you better at your primary job. Ie, if you are an accountant, you could still stand to learn some fine arts/speech/writing/drama/social sciences, which would make you a better employee and person.