Talk to any teacher or administrator who gives a shit about their students and were teaching before 2001. I come from a family of teachers and school administration and they all point to NCLB as a huge turning point downward in education. Even the ones who favor more standardized testing as a way of finding teachers who aren't up to snuff say the test score has to be one input to the equation, not the only thing. Making the test score all-important skews teaching the same way making one metric in business all-important skews the business toward that metric.