Providing a service and a customer base and a distribution system works out to a lot more than just "taking," but you do not see anyone complaining about that.
Dev's keep going to iOS because that is where they make the most money. So if developers want to get paid maximum revenue, they need access to Apple's Walled Garden.
As a user of the Walled Garden, I am willing to pay extra to keep the riffraff out. Release a good App (Yeah, Filmic Pro, I am looking at you), and I will pay for it. Android users have shown that they are less willing to pay, and must put up with more ads and spyware.
You are always free to make your whole enterprise web based. HTML5 and Java can get a lot done these days. If you want inside the Walled Garden, you pay the price of admission - as a customer or as a vendor. I may not see as many different flowers because some don't grow there, but I also don't see as many snakes because I am paying a premium for someone to keep them out.