As far as I can see there are three ways this happens:
1. They were writing a policy and either a senior manager saw the word IT and decided he wanted the IT team to be involved, or an overzealous IT manager, in an effort to justify his existence decided anything with the word technology in it had to be overseen by his team.
2. Every slight office reshuffle led to so many petty IT tickets that the team decided it was just easier to do it themselves.
3. And I hope this is true, at some point there was an office move where SO MUCH DAMAGE was caused to the IT equipment that a policy was created which means Doris from accounting can't even move the pot plant that's next to the office MFD without adult supervision.
Actually there's a fourth.
The office was a highly secure data sensitive environment. The policy existed purely to prevent any unauthorised devices being introduced. In fairness the IT dept weren't bothered about staff moving things however it was senior management paranoia.