My 4yr old struggles to reach the thumb stick of the Wii nunchuk and finds it hard to control. My daughter initially moved the nunchuk around with her arm to try and control the character - I had to keep telling her to just use her thumb on the stick.
The point is, to new users thumb sticks are not actually very user friendly or intuitive at all. With practice they work great as we know, but they ARE an obstacle to "getting into gaming". Touch screens are 100% more accessible, both my kids have no problem from the get go on the iPad. That's the problem, touch is not that great for many game types (platformers, certain types of shooters etc) but it is easy to pick up. Thumb sticks have the exact opposite problem.
Step back in time 25 years to the first time you played Sonic the Hedgehog; I can't be the only person here who used to move the pad upwards whenever I jumped! I'm just amazed it took the industry this long to see how it could be built into consoles.