Earlier quoted context omitted.
> Or you might think, "Ah-ha, desktop apps!" But the OS vendor can casually destroy you there. Casually? The amount of effort and goodwill, say, Microsoft would need to spend to prevent me from installing $PROGRAM on my computer is significantly higher than the amount of non-effort a single extension reviewer would need to expend to click "no" arbitrarily because they are having a bad day. How would Microsoft do it?…
The OS vendor could "destroy" you by making changes to the OS that affect your app, right? The Old New Thing[0] is full of stories of apps that exploited undocumented implementation details of the OS, and were surprised that those aspects were in fact changed in a later OS version. To its credit (though not everyone agrees), MS has spent a lot of effort making compatibility shims, basically doing other people's work…
You sound like someone who's made the mistake of supporting Apple