Here's the funny thing. Teacher tenure has never really been a fortress that protects incompetent hacks and abusers. It has functioned as a set of rules by which undesirable teachers could be--fairly--jettisoned, then have the decision to release that teacher stand. It gave teachers a reasonable period of time to establish their long-term worth (with the option to open the trap door quickly, in the early stages, for egregiously inept or shady folks). It also gave administrators and school boards a defined set of reasons why a teacher might reasonably be let go, after the district committed to hiring him.