They should go ahead and do that, then make an OS and mobile devices built around their store, so I have an option other than iOS devices when I want someone in my life who's not a tech nerd to have a reasonably safe and usable computing experience that's still very robust and doesn't require any work on my part. That would be competition and improved consumer choice.
I want more options that deliver the experience Apple does (or better! Please!) rather than fewer. That's the choice I want. I've got tons of only-nerds-can-use-them-safely computing options. I don't need more of those.
Apple cares about their hardware customers and fosters a well-earned trust. The AppStore rules are a huge part of the foundation of that trust.
What's Microsoft's parallel motivation in your analogy?
Desktop software, for a long time, did not have the notion of specialized app stores or enforcing signed programs. Yes, Windows has loads of security issues. But surely this can be a problem that can be solved over time?