I think this view is a bit myopic. Just because the controls are imprecise, doesn't mean the games can't present a deep experience. Certainly existing FPS games and RTS games would not do well on a touchscreen device. The reason why games on mobile and tablet platforms have done so poorly up to this point is that they merely try to emulate a genre of games that was built from the ground up with a different platform in mind (PC or console).
When GoldenEye first came out, the controls were abysmal compared to what was possible with Counterstrike on the PC. But console developers eventually learned to adapt (dual stick controls) and change the feel of the game to be console appropriate. This needs to happen for mobile and tablet as well. My hope is that the push to create meaningful gaming experiences will engender innovation in this space that nobody has seen yet (new game genres, new input methods, etc).
I'm not sure I follow your statement about exciting new genres being impossible on console or iOS...can you give an example about one such genre that is PC only?
I think, anyway. Maybe that's got nothing to do with it, and we see innovation on the PC solely because it's a more indie-friendly development environment. But I think it's telling that the dev versions of consoles come with keyboards.
Another genre many people shy away from on PC unless they're hardcore and money-rich: racing simulators. A controller, a wheel, or an accelerometer is a much more realistic input method for controlling both a steering wheel and feathering a throttle/brake.
Obviously both of those genres exist on PC, but they're quite a small marketshare of an already small marketshare.