“Teachers couldn’t teach what they hadn’t been exposed to, innocently training for an actual job rather than having the luxury of homeschooling their own children.”
This is why people like Bill Ayers went into indoctrinating teachers.
The Left called him a respected educator, by which those not sipping the koolaid will mean indoctrinator.
But as the OP sets out it was hardly new. Consider Dodd’s School of Darkness, available in PDF form online, which is an autobiographical account of a woman who departed from the communists.
Early on in the book we see how, in the form of a teacher she unwisely respected, how easy it is for a teacher to manipulate a student. If you read it consider that if the young girl had had a better grounding in the Faith she might have responded that there is a time and a place to everything under heaven to the teacher’s asking, IIRC, if Mideveal monasticism was something a girl of her age and era should be interested in. She could have escaped, maybe not entirely, but somewhat, that teacher’s baleful influences.
A number of people read School of Darkness looking in vain for evidence of more than 1,000 communists who were sent into the Catholic priesthood.
But more alarming, Bella Dodd showed how idealistic, secularly-”religious” young people were working for Communism, before frequent 180 degree changes in policy and ruthless purging of loyal people who were in the way, caused many to question that anti-God religion.
We told them to turn their brains off and be good little sponges.
And then we wonder why they can not think for themselves or believe things that are manifestly not true.