This is not a correct analogy to "bad information is worse than no information".

A better analogy would be a medicine that typically leaves patients worse off than they were before treatment.

Doctors have a maxim of "first do no harm." I believe that maxim is being violated by some of these attempted fixes.

I'm not saying they should give up the search for something that works, but they absolutely should not cause harm just for the sake of doing something.

What if the test makes good doctors quit? (As seems to be the case here.)

I don't think that this really fits into my analogy, but if losing a few good teachers is the price we need to pay for preventing a toxic culture of no-accountability where administrators are not allowed to make metrics-based decisions then so be it.

If you have the wrong metrics, you cannot make the right decisions. If you are throwing away good teachers because the rest are really good at gaming the tests then you have done far more harm than good.

The analysis shows that the test results contain zero information, unless you believe that teachers change quality randomly every year. If correlation begins to appear in those evaluations, it will be because the test has been gamed.