Sure, Apple has built up a platform with tens of millions of paying customers, and invests in development of APIs (though they certainly aren’t investing in any fucking documentation or quality control). But anyone with two brain cells to rub together can see that without third party apps there would be nothing left to invest in.
Did Windows Phone fail because the devices and system software were inherently worse? Of course not, it failed because Microsoft couldn’t convince developers to support it.
I know it’s in company interests to act this way—to the tune of dozens of billions of dollars—but when you read some of the things Cook, Federighi, and Schiller said during the Epic trial, it gives an impression that they genuinely do believe that all economic activity on an iPhone or iPad is thanks solely to Apple. Absolute lunacy.