Did you go to public schools? I did. The student body is mainly uninterested, incapable, or irredeemable. Some great diamonds in the ruff to be sure. But certainly these people would excel regardless of a 1-off actual good teacher seeing as most of them are just mailing it in, like their student body.

Why go to the trouble of getting a masters to waste it like this?

FWIW I don’t believe teachers should need a bachelors. A 2-year trade school should suffice.