Many public-school science teachers are not even educated as scientists.
Are you sure about that? At least here, to teach high school science subjects, you generally need to be qualified to do so. My wife has a BS and MA in chemistry, with an undergraduate minor in biology. This qualifies her to teach both subjects, if she takes the subject tests to get certified (she's only certified for chemistry, so that she doesn't have to teach bio). I'm reasonably certain that the entire science department has science, versus education, undergraduate degrees--in fact, my wife may be the only one with a formal education degree (MEd).
Actual scientists can command salaries higher than what teachers are paid, so very few people who graduate with a science degree are willing to work in a public high school.
This is not really our experience, but your mileage may vary. Before going back to grad school for her MEd, my wife was making roughly the same money working as a senior lab analyst. The benefits were a little better, though.