A related reason, that I mentioned in a comment a few weeks ago, is that some people in management who are required to be in the office resent the fact that their reports (who by the nature of their role definitely do not need to be working every day in the main office) are remote and that it helps their work/life balance.

The solution, I think, is for companies to properly define which roles are open to remote — perhaps it might be time for developers to receive a comp differential for being office-based — and to make work in the main office more appealing. Good food, a nice office, and other quality onsite benefits are ways this can be achieved.

[Disclaimer: I'm working remote now]