Neither Linux nor Windows but it’s a sensible guess :)

Nothing to do with Windows? Are we sure about that? Asus is a Windows OEM that pre installs Windows and has enough privileged access to insert a surreptitious executable compiled specifically for Windows.

Yes, agreed, if they chose a *nix like OS and they had root, they could do the same thing and that would be equally shitty. It is Windows OEMs that exhibit this kind of fsckery and yes we do have a choice.

Linux squashes root over ssh. An OEM could preinstall a sudo user to get around this but that kind of BS would be their death knell as a vendor.