As someone who's both worked as a teacher and as a software engineer, my feeling is that what happened in reading education is roughly what engineers' jobs would be forced by their CTOs to use software methodologies and languages that came from their university professors who've never really spend much time (at least not in well over a decade if at all) doing actual salaried software development where code had to be…
The source is corporations which sell curriculums which are mandated by regulation. These curriculums are designed to be easy to sell to governments, which means they tick all the regulatory boxes, but don't actually teach.
Our public education system is not designed to educate, it is designed to return profit to a few corporations which supply it.
How do I know this? Sister is a professor of education and has to fight against this stuff all the time.