Hrmm, some not all.
I’m quite happy to have them assess my students.
Here's the thing: if the good teachers endorsed the idea of merit pay, then they'd be rewarded for good performance while gaining respect.
The collectivist union mentality would tend to diminish the motivation of some potentially good teachers, unless human nature has changed recently.
One of my sisters recently retired from teaching and observed frequently that some of her co-workers were as dumb as a box of rocks.
After her retirement, she taught a college course the purpose of which was to instruct currently certified teachers how to teach math.
How many students have been damaged through the years by being subjected to unqualified teachers who, though certified, have no mastery of their subject?