IMO that's mostly the fault of Windows not having a real package manager for so long. There's no way for software to know that it needs an update unless it runs a background service to constantly check. So either your users constantly run outdated software (which is one of the reasons companies love offering their product as SaaS) or the users have to check manually (which users won't do). Some software checks when you run, but a lot of times I just need to open Excel and get to work, so I'm going to click "Skip this version" and keep going.
Honestly I don't see really any good way to handle it without some background service. It's just nicer when the OS has a way to handle it built in.
> There's no way for software to know that it needs an update unless it runs a background service to constantly check.
That is required only if you need to update the app when you are not using it. Apps can check for updates when you run them and then let you decide when to install the update/or skip it/etc.
Package manager would be good, but not possible on Windows given the amount of commercial software. Companies are not going to seed control to the Microsoft when they can potentially up-sell you via their b/g update services or do other kinds of advertising. I doubt MS would want to play rough with their partners either.
Honestly I don't see really any good way to handle it without some background service. It's just nicer when the OS has a way to handle it built in.