Do we care more about student progress or our appearance? We care about both, and we have to. Proposed solutions will have to cater to this reality to have any hope of success. Why can’t we start a movement to walk away from these tests? Because a ton of scared people think the tests are the safety net of education. They are the last resort. If you got a bad education and can still past the test, it's a quantifiable…
The reality is that many of the schools, and many of the teachers, are just bad. This can't be acknowledged in the public debate, so it isn't addressed. The unions have established a structure dedicated to protecting bad and mediocre teachers. Which is why great teachers can't get paid appropriately -- the unions would never allow it. It's also why teachers don't enjoy higher status: As a group, they really don't deserve it.
Yes, the unions are right that, without tenure and their workplace rules, teacher hiring and pay would be a political game. That's what political systems do, they respond to political incentives. That's the whole idea of charters: to move the accountability of the schools out of the political system and into the hands of a constituency invested in actual quality. It's probably true that _today_ parents as a group aren't completely equipped to handle that role, because they've been trained to just send their kids off to school. But as they get the opportunity to make more decisions and influence the schools' offerings, they'll come up to speed.
tldr; The testing apparatus is a symptom of a broken governance apparatus. The solution is to fix the governance and incentives. So long as the incentives are political, the results will be political.