TL;DR: The writer, a math teacher, is quitting (edit: his) job because of increased bureaucracy and standardized tests. Mostly, it seems, standardized tests. The problem is, math is the subject which is BEST served by standardized tests. There is really no fuzzy aspect to K-12 math: answers are right or wrong. And there are of course many benefits to standardized testing like teacher and school evaluation, providing…
Same with high-school CS. You're not really going to learn a lot of specifics in high-school CS, and what specifics you learn are unlikely to be that important. What's important is to learn computational thinking. The tests, however (at least when I took the AP CS test) only tested trivialities, stuff like the syntax of a particular corner of the C++ STL, and the course was therefore set up mainly around that. We literally spent about a month on minutae of iostreams! In an introductory course where most of the students had never programmed before! I could hardly imagine a more stupid way to teach introductory CS, and can't imagine it could've been invented except via ease-of-testing brain damage.