I went to a public university and they determined which mathematics class you started in by your ACT/SAT or AP test scores. I guess I'm just struggling to see w

I went to a public university and they determined which mathematics class you started in by your ACT/SAT or AP test scores. I guess I'm just struggling to see why a programming course would be any different, or why a placement test would be prohibited when they're already using the standardized test scores as a placement test of sorts. Unless things have changed in the last five years.