i've seen the argument made that politicians should not be allowed to announce their own candidacies, for similar reasons. the argument is that nobody that chooses to run could be anything better than corrupt, so the only way to get a clean system is for the masses to nominate people - and possibly against their will.
i think a similar mindset needs to be adopted with teachers. i've spent a good deal of my life preparing to become one, but in the end decided it would be a horrible job. i'd be the kind of teacher that would make no effort to reach out to struggling students and would happily fail 75% of the class if it didn't hold up to my expectations. then, they'd pull this circular argument on me that i'm not meeting expectations. so, i wouldn't last very long. the core of my disinterest would be a complete inability to discipline the children of strangers. that's a totally foreign - and somewhat frightening - concept to me.
what kind of mental illness does it require to want to stand in the front of a room and enforce this neurotic, hierarchical structure down on kids? so, how can we speak of "good teachers", in the context of the mentality that the profession requires?