I totally agree your average end user is poor at managing updates themselves and thus it is justified to enable auto-updates by default. What that does not justify is totally removing the ability to turn them off. Feel free to make it a little harder to disable: the user has to run a CLI command or something, but the option should be there.
> How can these be addressed if upgrades are not forced, are there standard processes followed that provide the best compromise for both vendors and end users?
If you go through the extra effort to disable updates and don't grab a security fix, that's on you. How is "you have to do exactly what I tell you - wait why is nobody using my software?????" a best compromise for users? What are users expected to do when an upgrade breaks something and they can't downgrade?