The button acts as a mist setting/washer fluid while opening a panel in the touchscreen UI to then tweak auto/high/low/off. Tactile controls, that can be operated by feel without taking your eyes off the road, are important to both of us. Voice commands for higher functions/problem spaces makes a ton of sense. It's why I never overrode the safety lock in my care that disabled the touch screen when it's moving more than 10 mph. If the cars voice system or Google's voice system can't get it, it is probably high level enough that it can wait until I stop. If it's low level/time sensitive enough, I want a dedicated input.