Standardized tests are good for some things, like measuring aptitude for medical school. Therefore, tests are good for things they weren't designed to do, like evaluating teachers (even though they aren't).
By this logic...
Hammers are good at hitting nails, so they are good for removing screws.
Hot fudge is delicious on ice cream, so it is delicious on breakfast sausage.
Michael Jordan was the best basketball player of all time, so he was also the best baseball player of all time.
Billionaires are good at making money, so they must be good at making education policy.
Have I made my point? If not: