Your point isn't applicable.
Right now, the indicator of mobile platform success is the robustness of app stores. It's all about quantity now. Only over the past two years did such a thing as an "app store" emerge with any kind of public notice. Apple seems to have perfected it (relatively), and not only does the competition have far fewer apps, for many of them their app store paradigm isn't implemented nearly as well as Apple's.
Apple is bragging about app quantity because at present app quantity is a key selling point. It's an indicator of the robustness of your monile platform, whereas only a couple of years ago there was no such thing. There was barely such a thing as a "mobile platform" to begin with.
As the competiton gets their stores on track the focus will eventually shift to other aspects and features. Right now, Apple is milking the App Store feature because consumers have decided the number of apps you have on offer is a big deal.