Why do the patents need to be in the same area (ppl keep saying that, but I don't understand why they have to counter-punch in the phone market)? They have pate

Why do the patents need to be in the same area (ppl keep saying that, but I don't understand why they have to counter-punch in the phone market)? They have patents on pretty broad things, non-phone related things, like MapReduce. Doesn't seem to be worthwhile to be an Android manufacturer. Lawsuit from Apple and licensing arrangement w/Microsoft.