I, on the other hand, am tired of being called in to investigate why the janky Excel macro written four years ago by an ex-employee doesn't work for all the external stakeholders this manager just sent the spreadsheet to, only to find that the hardcoded database and local admin user creds in the VBA script are now leaked and in the clear.

A lot of people pushing shadow IT "solutions" wildly overestimate their own ability, while maintaining garbage-tier information security standards. That doesn't sound like you, but it's the far more common situation those of us in "IT" are forced to protect the wider organisation against.