You can classify degrees by the portion of students who end up doing something directly requiring that degree. Suddenly, it becomes clear what is going on.
Your high school guidance councilor probably told you that the degree wouldn't matter much, which is correct for somebody like him. For a large portion of the population, a degree is purely signalling. It shows you are a more upper class, more able to plan ahead, more willing to show up every day, and more willing to put up with nonsense. People with these sorts of careers are fighting to out-signal each other. If we made a bachelor's degree free, they'd need a master's degree. (actually already happening, even w/o being free) If the master's degree were standard, they'd need the doctorate. The skills actually demanded require no such thing, and would've been beneath high school 80 years ago. It's an arms race, pure and simple. Individuals may benefit from getting to the top, but it does our economy no good to encourage and support this. Keeping people out of the workforce while diverting money toward funding the arms race is harmful.
On the other hand, there are degrees for which most students end up in a career that more-or-less requires the degree. Famously, it's the STEM stuff, but this also applies to nursing. We know something from the fact that students end up taking jobs which require their degree: these fields are not purely an arms race. These fields can still take more people. These fields have degrees that are of value beyond signaling. Our economy would benefit from getting more people into these fields.