Perhaps they want to make some exclusive deals with Apple in the future, and don't want to go through the hassle / bad publicity if they disable the Amazon API

Perhaps they want to make some exclusive deals with Apple in the future, and don't want to go through the hassle / bad publicity if they disable the Amazon API on mobile devices in the future ? Perhaps they have some plans with the Kindle and are afraid that having other mobile devices using the Amazon API will hurt those plans ?