Ah, I think I see the main contention.
Most of the time I hear folks talking about "teaching to the tests" they are upset that they are just getting kids so that they can pass the tests. Indeed, even one of your complaints was that you had to compromise your teaching so that they could score better. My point is that if that is the concern, they are failing even at that. Test scores are going down, such that most of the arguments that they learned the tests, but not life skills, are moot. They aren't even passing the tests.
That is, I didn't mean to claim that they simply started during declining scores. I meant more that the scores are declining now. If the concern is that they are "teaching to the tests", my bigger concern is why are they so bad at that, even?
For timing, the assessments seem to be that they have been declining steadily since 2012. If your claim is that the "teach to the tests peaked in 200x" and that that is why tests are failing, that should have started reversing with kids this year? (I assume the assertion is there would be a 7ish year lag on kindergarten kids getting to age 13, to be reflected in this story. Obviously not a full step function, but I don't have a solid model on that. Love it if you have one.)
To that end, my assertion would be that if they were at least able to pass the tests, that would still be an improvement over where we seem to be. Test scores are falling. Why? It can't be that teachers are just teaching to the tests. Or, rather, if it is, they are doing a bad job at that, even.
I'm assuming the idea is that the kids are passing lower level tests better, but failing later tests? I'll take a quick dive on some of that later, to see if that hypothesis holds up.