The ability to fly a plane in zero visibility is based heavily on the pilot...the pilot can do this with or without glass touchscreen controls. They did it with older avionics with physical knobs and switches as well. There are plenty of pilots without an instrument rating (meaning rated to fly with little/no visibility) who fly airplanes according to visual flight rules that take full advantage of glass cockpits. It would be ludicrous for a pilot who is only rated to fly visually to fly with the windshield covered, and yet, they still use the touch screens without problems. In the automotive world it would be equally foolish to drive without being able to see out the windshield, but that doesn't mean that a touchscreen won't be useful for everyday driving controls.
I'm not trying to be argumentative, I'm just reading posts and seeing a lot of gripes about things that people really haven't had a chance to test out at all. There were so many gripes about the lack of a sunshade for the pano roof that by the time test drives came around, Tesla had already come up with an ugly, half-baked sunshade that we all now have to deal with if we want the pano roof. I just would hate to have a similar things happen to the dash with the addition of ugly, afterthought buttons when we don't even know if they'll be needed yet. The touchscreen may do a beautiful job of being functional, we should give it a try!