I worked in public schools for over 3 decades. This kind of activity has been going on that long, at least where I worked.
The way they justify it is to call it “helping children learn to become good members of their community”, actively contributing to society.
IIRC, this goal was an officially-stated educational goal. It is mostly applied to their efforts in turning the children into environmental activists.
When I was a kid the teachers kept their political views to themselves. We also had a good share of normal men.. WWII vets teaching math, sciences, drafting and such.
Now that the profession has devolved into an ideological cesspool wherein no light can permeate, how many good role models remain?
I can’t imagine those same types of men (or anybody rightly-wired) being able to tolerate the control-freak harridans running the current asylums. They all have a target on their backs. The innocent children lose on multiple levels.