The definition of "good teacher" they seem to be using is some variant of the "value-added" model, by which teachers are evaluated based on how much the test scores of their students improve. However, the tests are only barely valid (if at all), and don't measure much (if anything) worth measuring.
Meanwhile, the reading and writing go by the wayside in favour of multiple-choice "comprehension" questions, math becomes an exercise in gaming in the arithmetic, and science (held up so high in theory and so low in practice) becomes a glorified exercise in vocabulary memorization.
This isn't even beginning to mention the arts.
I'd have more faith in Superman if I thought schools knew what they wanted to do, or if there were a cohesive and coherent philosophical approach.
As it is now, there is a system which reduces good teachers, protects bad teachers, and hamstrings learning in favour of that which can be easily measured and that which can be taught with only a modicum of thoughtfulness required.
Wake me up when "education" is something other than scripts delivered to teachers by bureaucrats and specialists who haven't ever felt what it's like to actually teach.