60% of Americans CHOOSE to own a phone that has those features...

I think that is the issue. Android offers (nearly) all of the same functionality and yet people still choose iPhone.

Abusing your ecosystem is one thing (ex. defaulting to Apple Maps for location links, only allowing Safari as default browser), but not allowing 3P app stores seems perfectly within a company's rights.

Amazon isn't forced to list your product and Apple shouldn't be forced to give you access to it's hardware/software users.