I would guess it's because Apple are a hardware vendor that at least talks about privacy as a selling point.
The M series chips provide large amounts of GPU RAM so I think people can see a world where Apple sells local first, privacy focused, inference based on hardware sales.
I'm not pitching Apple as the best or only solution, I'm saying that selling local inference seems to fit with their current marketing goals.
Selling high end, high margin computers that have lots available GPU RAM with at least lip service to local inference for privacy fits with what they already do.
I don't see anything to stop say Framework making the same pitch but with Linux but since Framework don't design their own chips they don't have quite so many levers to pull as Apple do.
The M series chips provide large amounts of GPU RAM so I think people can see a world where Apple sells local first, privacy focused, inference based on hardware sales.
LM Studio's strategy seems to fit that very well.