I think if moderation of the apps you can install on iOS was going to become a legal issue, we would have already been there. The reality is, if Apple wrongs you, you can walk into Best Buy or whatever and buy and Android phone.
The smartphone ecosystem is very healthy, there are plenty of opportunities for everyone to get exactly what they want.
If you buy an Android you can no longer commuicate with all your friends using iMessages. SO no, not quite "plenty of opportunities for everyone to get exactly what they want."
The smartphone ecosystem is very healthy, there are plenty of opportunities for everyone to get exactly what they want.