1) Graduates are treated like cr-p and are expected to suffer with low hours (0.5 FTE), poor pay and massive work loads whilst they 'earn their stripes' in tenuous employment situations.
2) Managing problem classrooms is akin to being thrown to the wolves - support from management is, at best, tokenistic. There are no real consequences for unacceptable behaviour / results.
3) There is (can you believe it ) no such thing as an unnacceptable result. I clearly remember being directed to 'mark up' shoddy work 'for the good of the school' in terms of numbers / rankings.
4) As a male, I quickly became sick of being scrutinized, fished and baited on a range of issues revolving around female students (from dress codes to content matter and... on and on).
Now I teach crims to walk and talk like members of society and maybe impart a few skills along the way.
In many ways there are eerie parallels with the state school system, but ( and from a purely selfish point of view ) I'm not expected to take it home with me.
As a teaching professional, I can think of no other area to be involved in that is as unprofessional as the state school system.