I think the worry is a locked bootloader.
We really haven't seen such a large technological separation like this. At least back in the old days you could still run what you want.
macOS moving to the iOS route where you have to jailbreak your device to get any sort of usability out of it is not a space I want to participate in, and yet it seems that's how the entire Apple line is moving. They're almost the complete opposite compared to Microsoft these days.