That's really sad when you think about it. It implies, on average, our minimum viable college students go into education. Not our best and brightest. Who ends up being the majority of the people teaching our children? Probably those same people.
Given the inefficiency/pointlessness of much of the effort involved in compulsory education, I'm not sure better teachers would be able to significantly improve the system. We need a structural change here first, and only then start to look around for brigther people. Otherwise, any bright people that may enter the system, will eventually be frustrated, give up, and in the end achieve results (in the field) that are no better than those of the borderline-acceptable teachers.
If you do things this way, the effectiveness of the current people is likely to suffer (in pretty much any area, not education specifically).