In short, this is Apple way of viewing things: This is our platform, is our way of doing it. You don't like it? Sorry.
As it stands now, Apple has enough influence on the development community, to do as they please. Weather we agree with that or not, it's irrelevant.
So, they'll depreciate APIs based on their needs, not developers. And Apple is very strict on that, if you use you own API inside your app, or use an API not supported or not allowed in iOS, they have the right to reject your app. This you know before hand, so you avoid losing work because of this, again, these are their rules.
As many have said here, it will all depends on you business plan. I do consider Android more flexible, if you manage to get a chunk of Android, for sure you can thrive without iOS. But let's assume that scenario, that your app is really successful in Android. Then iOS users are begging for an iOS version, what would you do? If you don't cover iOS, for sure (given the hypothetical success), somebody else will find a way to offer such a product for iOS. Would you guys be comfortable giving that piece of the market to someone else, just because you decided that iOS doesn't support this or that API? Or you adapt your product so it uses Apple proper APIs?
The choice is yours.
Best of lucks!