When will touch gaming take off?

I know Windows 8 is still new, and the majority of computers sold are still not touch screen, but between the iPad, some android tablets, and Windows 8 tablets, I can't understand why more serious games don't have touch controls.

By serious games, I mean full PC or Mac games. Some iPad games are getting there, such as GTA, Sid Meier's Pirates!, and sports titles like FIFA, Tiger Woods PGA, and others. But Civ 5 is the only game I have heard of recently that utilizes touch. I personally have not been able to use it, but I have heard it is good.

My main problem with these iPad and Android games is that they don't seem to be as full featured as true games, and use micro-transactions (which I hate). Sim games especially seem like they would fit really well for touch controls, especially since shooters and other fast paced reaction games are tough with touch controls, and work better with controllers or a keyboard and mouse. I'd love to see a real "The Sims," not The Sims Social, which I was very disappointed with. Sim games, "X" Tycoon, or Sid Meier's games (such as SimGolf), or even some RTS games would work so well with touch controls.

When can we expect these? What are the road blocks? One of the main concerns I can see with high quality games that would use touch controls is the variable screen size. A 7" tablet is very different than a 15" laptop, and using that real estate effectively could be challenging?

Any thoughts?