I have a question. A what if scenario. Say 13 years ago, Apple entered the market with an iPhone. But, in this market there was:
1) Palm
2) Microsoft
3) Blackberry
4) Nokia
5) Motorola
6) Sony
7) Ericsson (I feel like I spelt that wrong)
8) 6 & 7
9) Google with HTC
They all had a mobile device, and they all did their own things however they saw fit. Some had stores, some could just download apps from the internet no restrictions, some had zero apps, etc. Then, as time passes. Most of them fail. Not because Apple and or Google stopped them. But because people made a choice. They picked Google Android and or iPhone iOS.
There are no laws broken, and no illegal means in which either became as successful as they are today.
Now, 13 years later. Neither has been declared a monopoly. Neither have don't anything to prevent another business from starting up a mobile device company with a competing OS and AppStore.
They just don't want someone else's store within "their" store. I don't think it would be fair to force another store within another store that didn't want it.