User Interfaces are dying - Why?

Why aren't user interfaces changing? Why are they so stagnant and why is it that even if something comes out that are even barely revolutionary, we still fail to embrace it.

I think the answer lies within our behavioural patterns. We humans are really not willing to change, no matter how good the change might actually be for us. It boils down to comfort levels. Sometimes, we get so comfortable with certain interfaces, be it computers, cars, appliances etc. that even if someone was to come up with something really novel we would look the other way as if nothing has happened. How many times have people tried to do things and the people just looked the other way. Why is that? Why is that we get so comfortable with certain things and are not willing to change? Why?