I wrote a book about speech recognition -- and I _wrote_ it, I didn't speak it. I discovered that speaking uses different mental muscles than writing does. That's fine, because some people are more comfortable with one than another (such as doctors who are happy dictating but don't want to type).

Also I remember when computer mice were new, and plenty of people said, "I can't imagine using that."

I think that's true of other types of user interface as well, from haptics to whatever comes next. Sometimes you have to envision what _could_ be, and discover from experience what reaches people... or a subset thereof.