Because it's the 11% that matters. I mean this honestly, I'm not being dismissive. I could point you at plenty of data to back this up, but the simple fact that almost everyone's app goes iOS first should be sufficient to indicate that it's the platform that matters most.

Side note: I've got both iOS and Android devices, and nearly every app on Android feels like a cheap knockoff of the iOS equivalent. I can't think of a single situation where I prefer the Android app over the iOS app.