A guy walks into an AT&T store and wants an iPhone. He'll get an iPhone.
A guy walks into an AT&T store and wants a Windows Phone. He'll probably be talked into an Android.
A guy walks into an AT&T store without a clue. He'll walk out with an Android. It's the most profitable for the carrier, because it's perhaps the only smartphone left that grants the carrier full control over how it's configured and what software is bundled.
Patent attacks against individual Android manufacturers and individual models are irrelevant. Your carrier will always have a wall of indistinguishable Android phones for the next customer to choose from.