Almost all careers are either certification-based or they create an arms race of education. When you have an arms race everyone has an incentive to get a degree but perhaps not everyone with said degree will get a job. Resources are wasted, but there isn't any incentive to stop the system from perpetuating itself. When you have a surplus of unemployed-educated people, why not hire over-educated workers? This reenforces the need for a degree.

Every time I see people saying "not everyone should go to college" during a non-economic-boom I wish they would start teaching game theory to high schoolers.