This is not true. Mobile platforms do help with tapping on small elements. E.g. HN isn't mobile friendly "as is", but I have no issues with tapping any of the links. I've also used Exante mobile trading terminal for some time and had no issues with it either.
I agree that accessibility still is the concern, but watching my grandma struggle with her tablet, it's mostly the fact that buttons aren't buttons and everything jumps around like clowns in circus and cannot stop, instead of being a proper user interface. I bet she'd have similar issues with appliances if their design was just random flat symbols on white surfaces that randomly disappear.