I think that if apple were concerned about market share, iPhones would be on every carrier, there would be more iOS phones available and the pricing would be more competitive. I think that they are more happy to be a 20-30% market share with a semi premium product than a commoditized less capable product. The reality is that apple will never be able to compete with hardware vendors that crank out good-enough phones with a cheap yet very capable OS on them. I don't think they want commodity products in their line up. I also think that they may feel similarly to what steve jobs said about Microsoft in the 90s. For apple to win, google/android doesn't necessarily have to lose.
As for the litigation, I don't know that it is necessarily tied to the fact that android has taken off so well. Like it or not, most hardware vendors use apple as a hardware benchmark, so copying their products is inevitable. I would not want to sit idly while other people make knockoffs of my products either.
As a almost exclusive Apple product user I am happy with Apple having about 20%-30% market share in major category it is competing as well. (Mac may never reach the goal, but then again as long as it is doing well.)
I'm uncomfortable with iPad's share to be honest, it's not healthy.
As for the litigation, I don't know that it is necessarily tied to the fact that android has taken off so well. Like it or not, most hardware vendors use apple as a hardware benchmark, so copying their products is inevitable. I would not want to sit idly while other people make knockoffs of my products either.