That’s because people who are teachers have EDUCATION degress, not degrees in what they are teaching! This is a really stupid way to train teachers. The emphasis is all wrong. Teachers should have the majority of their training in the subject they are teaching with a just a FEW EDUCATION classes.
Hillsdale college is no longer offering teaching degrees without a 4 year degree in something real.
I'm pretty sure that what you are saying is somehow "rascist"; but, personally, I think it is logical. Which is why you will never find it in a public school. I have never understood this philosophy that if you have an "Education" degree, that means you can teach anything. It is ridiculous; yet, that is where we are today. No surprise as to the failure of schools when this is what they think. I remember talking to a woman who had been a teacher before she had kids and she was telling me that when she came in one year to get set up for that school year, she was told that she was doing the "special ed" class this year. She told them that she had no training in "special ed" and she was told that it was "her turn". This was years ago, and probably the first hint I had that something was wrong with the public schools. (My kids had Catholic education.)
There is a book by Thomas Sowell, can't remember the title, but, he stated that education would improve greatly if there were no such thing as an Education degree; but, that you needed to get a degree in something, and then the "teacher training" could be either a Masters program or a Certificate. I thought that made a lot of sense.