In my experience, high school and lower grades teachers are educated with a general education, and then are assigned to teach various classes based as much on seniority as on knowledge. You can have biology taught by the same teacher that does phys ed or home economics.
I guess it must be location, then. The highschool I went to had a very knowledgeable set of teachers, with the older ones generally having a better grasp on their subject matter. My chemistry teacher, for example, really did know chemistry and I honestly cannot see how anyone could have taught the material he taught without knowing it at a rather deep level. Not all my teachers were as bright, and some were more knowledgeable in certain aspects of their subject matter than in others. On the whole, however, it was very clear that the teachers in my school weren't placed based on seniority or any other ass-kissing system.
So I guess my opinion was biased.
When we lived in Mississippi our son had an english teacher that said ain't regular like.
Well, 'ain't' is a word, and English is capitalized.
And I don't think many teachers are well equipped to teach science.
I'm sorry you've had this experience (if you have). My experience has been quite different, though. Actually, funny story. When I was in 10th grade, my family took a trip to California. While there, we met a gal in a waiting room who was working on her homework. She said she was in 12th grade; she was doing 'social studies' using the same book my brother and I had used... when we were in 9th grade!
So yeah... I can totally see there being big differences depending on where you live.
Jon
Love your enemies!