I'm sympathetic to your reasoning, and I actually think your conclusion about how people wfh is probably true (a minority finding it wildly more productive) but the problem I see is that most execs don't understand what a lot of their employees do on a day to day basis, nor do I think they could properly understand the data even if they had it as a result. And, if they did have it, why don't they show it if the conclusions are so self evident?
In reality I think it's much simpler: the work that executives (and some upper level managers) do relies on a certain amount of theater. They need to be seen (in person) and they to be seen doing work (in person). That's part of the "deal" with being an exec --- you need to be able to act the part. Then, they just assume that's how it should or needs to be for everyone else.
The interesting thing is that "Darwinism" will sort it out for us in the long run. If the execs are right: more work gets done in the office, those companies will do better; if people are happier and more productive at home, those companies will tend to do better.
In reality I think it's much simpler: the work that executives (and some upper level managers) do relies on a certain amount of theater. They need to be seen (in person) and they to be seen doing work (in person). That's part of the "deal" with being an exec --- you need to be able to act the part. Then, they just assume that's how it should or needs to be for everyone else.