Wired connections are inherently more difficult to attack. In security critical applications banning bluetooth is perfectly reasonable.
The best way to correctly fight Shadow IT is to provide equipment and services so good nobody would even care using something else.
Some people will always want to bring their own equipment, but a lot of it is caused by penny pinching or lack of options
It quickly grows past the 2-3 sanctioned models. Everyone wants something not on the list, lots of bickering of "why was that model chosen?", etc. Well that pre-approved model is $150, this is only $175. Bob got that $175 model, this is only $200, it's not that much. Jenny got that $200 model, this is only $250. Jenny's got a $250 keyboard? I gotta upgrade, here's this $300 model... Wait did the company just buy Bill a 55" 4K display? I need that too...
Suddenly your $150/person budget has exploded to replace everyone's equipment for $1,000+ otherwise it's just not fair someone else got more.
Personally I'm fine with me buying and owning my own kb+m. Maybe give a once a year or two office hardware stipend or whatever. Then otherwise make basic stuff available for free. If you're wanting a $200 keyboard you're probably wanting a particular $200 keyboard, and it's probably not one of those 2-3 approved models.
It sucked. Big time, but they had the clout.
Remote work at startups has largely removed my need for this kind of behavior. Now I'm mostly just mad that I can't always run Linux at work anymore.
Same here, though I've never been in a significantly restrictive place with no authority (in current long-term DayJob I have some involvement in decisions wrt what restrictions are appropriate, and what exceptions to them are appropriate).
If someone is in a truly restrictive environment, they should take care. A deliberate breach of policy could be a job terminating excuse, or at least further justification, if someone wants them out of the way for any other reason, and in such circumstances a workaround and a breach will be seen in the same light.
Another thought around this is that I don't even think there's anything intrinsically insecure about BT as an attack vector but most likely some old policy based on security issues that existed in the early days of Bluetooth. Or at least I don't know of any, but I'm no expert in this so I would love to hear other people's insights here.