If it isn't productivity (or morale) driving their decision on "putting their foot down and demanding no work from home", what is it? I don't believe it's some simple reductionist "they're evil and want employee control" narrative.
Unfortunately, my background is in data science. I would say the field of psychology is better suited to answering that question.
Remove the "they're evil" part and I don't see what's reductionist about it being about "having more control over employees"?
That to me sounds like a very likely explanation.
Why, exactly?
1) Working in an office full of people is what they personally prefer, and
2) They have large investments in physical infrastructure that they need to use.
Why does it matter what leadership prefers/why do they prefer it if 80% of their employees are saying "I'd rather work from home / going into the office in inconvenient for me / I'm just as productive at home"?