this what many of us keep mentioningPrincipals said they thought it was pointless to give critical judgments of tenured teachers. They also said they didn't want to deal with the grievance process that often accompanies poor evaluations, according to the report by the New Teacher Project, a non-profit focused on teacher quality.
management is not doing its job
they are allowing inferior teachers to remain in the class rooms only because they refuse to do their job - managing staff
it is not teachers
it is not unions
creating the problem of ineffective teachers being allowed to remain to inadequately teach class after class, year after year
school management needs to be made to do its job