That's part of the problem, too. Public schools do a very poor job of teaching science. My point extends to that realm as well.
What are they good at besides political correctness and silly zero tolerance codes?
My thing is history. I terrorized a first year teacher trying to teach high school world history course because the textbook was poor and I knew more about the subject than she did.
I have to admit, though, thinking back on it that I did have a few good ones. It would really help if teachers took degrees in the field they will teach and then added on a year of professional school rather than taking undergraduate degrees in "education." At least they would know something about their subject.