Teachers are not in the profession to listen to why little high school age Johnny did not get an A on his paper, not the least because you, the parent, helped him write that paper.
Not implying there aren't exceptional students, but they are exceptions. And for everyone else, we train them to be good factory workers for the disappearing industries of America. The one thing we all agree on is that the system is broken.
And then these same kids are sent home and asked to complete creative work, as if we had been training them for a creative job all along. We do not do this, but we expect the results nonetheless. And teachers pat themselves on the back for letting their students "get creative" while upholding the authoritarian system 99% of the time -- which they have to do, because it's their jobs on the line.
So no, those statements are not contradictory.
It, like the unhealthy hours of school for teenagers, is a product of parents wanting babysitters in many ways more than they wanted well educated children. Homework can be busywork to keep kids occupied when parents don't want to have to try to inspire them productively the third of the day they aren't in school or (should be) sleeping.