You don't think humans have the capacity to see something and understand that it's not practical?
I've used an iPad to type, and guess what? it sucks.
In the same fashion as an iPad, you'll have to take your eyes away from the screen to look down at the keyboard to see what key you're touching. Nothing will ever beat tactile keys in the realm of typing with your hands.
Watch how painfully delicate the tech blogger from The Verge is while typing, and keep track of how many times he has to hit the touch bar multiple times because he failed hitting the button correctly.
I refuse to pay $600 more for a down grade in productivity. Just because Tim Cook and the rest of his out of touch senior citizen team thinks it's cool, doesn't make it better.
So please, enough with the touch bar already.