I have been a public school educator for 13 years. Firing bad teachers would improve my morale immensely. It’s very frustrating to know that the lazy/racist/apathetic/clueless idiot down the hall is getting paid to be a marginal-at-best babysitter. Bad teachers do inordinate damage to our profession as well as students and make everyone’s job even more difficult. To paraphrase something I read in Harper’s many years ago, no one works harder than a good, conscientious, caring teacher, but there’s no one lazier than a bad one. (This is probably true in many other fields as well.)
I would love it if good principals with common sense (another kettle of fish) spent more time in all of our classrooms. Many do not out of a fear of being accused of micro-managing, time constraints, and/or an “ignorance is bliss” mentality. Conscientious teachers welcome observation, professional guidance, and constructive criticism if they know they are truly valued for their hard work, being treated fairly, and given real power to do what is best for their students and their school. Under these more ideal conditions, average teachers also become better, and ambivalent or stumbling teachers emerge from the gray areas with the skill and motivation they need to continually improve their classrooms.
On a completely unscientific note, I would say that, contrary to some of the percentages I’ve read here, the good generally outweighs the bad. Most people have more meaningful experience throughout their lifetime with teachers as students and parents than they ever will with other professions (and yes, teaching IS a profession), and will thus be more likely to encounter—and remember--the bad apples.