> Your desktop does not have much private data (other than your files, which reputable programs don't scan without reason)
Disagreed. It's not just about files; once you run an untrusted binary on a desktop it will typically be able to capture your screen, keyboard input, etc. It doesn't need to be in a file for malicious software to be able to pick it up.
In contrast, mobile applications typically run within a sandbox where short of an OS/kernel exploit there is no way for the app to access anything else but its own data (besides a very limited subset like photos, etc that you still have to authorize explicitly).
Disagreed. It's not just about files; once you run an untrusted binary on a desktop it will typically be able to capture your screen, keyboard input, etc. It doesn't need to be in a file for malicious software to be able to pick it up.
In contrast, mobile applications typically run within a sandbox where short of an OS/kernel exploit there is no way for the app to access anything else but its own data (besides a very limited subset like photos, etc that you still have to authorize explicitly).