[decafninja]

There are two facets to this.

First, productivity concerns are (mostly) an excuse. The real important thing that is desired is to be able to exert managerial control over employees. This is more easily done when you have employees in the office under watchful eyes.

Second, in an ideal world the people that like the office will commute to the office, and the people that like WFH will WFH.

The prefer-WFH people don't lose out either way from such a setup. However the prefer-office people still lose out, if, for example, the majority of a team chooses prefer WFH. What happens to all the social and organizational benefits of working in the office if you're in a team of 10 and only 3 people choose to come to the office? Or worse - if you're the only one? So it becomes an all or nothing scenario.