I don't see this as an accurate comparison. You can already rent a space right next to Walmart and open your own store if you like. Yes, I may have to pay a landlord, but again, there's competition among owners of land that keeps rents at a market rate.
You can think of the space within an ecosystem as virtual land. Apple has a monopoly on this virtual space. They can charge whatever they like, there is no competition.
The argument of choose another phone is different, because it requires spending a large amount of money for the right to entry. To many people this is cost prohibitive.
I don't have a personal stance on what the outcome should be either way, need to dig into it more.