A combo of management control and a very tiny number of people who abuse any freedom given to them, then blame you for not telling them they couldn’t do it, and then blame you for singling them out.

As an anecdote - we had no sick leave policy at a previous job. It was just tell us when you’re sick and you won’t be in. One guy joins and starts calling in on Mondays, or Fridays of bank holiday weekends. He eventually got caught saying he had been on a trip on one of those weekends and was called up on it. He told everyone it was bulshit because he was being singled out and targeted unfairly. Then we got a sick leave policy that applied to everyone.

Unsurprisingly, this guy was also the reason we needed permission to WFH, had formal expense limits when travelling, and core working hours during the day. He ruined it for 30 other people because he took advantage of every flex we had.