One of the reason there are so many iphone apps is that the people developing the apps themselves own iphones. If everyone making iphone apps can port their app

One of the reason there are so many iphone apps is that the people developing the apps themselves own iphones. If everyone making iphone apps can port their apps to android and test them on the phone they already have, then there will be more android ports of iphone apps, which means less value in the iphone platform. That's why Apple will not encourage this.