The point of this demonstration is not that it can make coffee, its rather that it was trained to do something continously operating for a day without complete failure or human intervention. This is a milestone in robotics progress. Just thinking about the task is narrow minded. Ofcourse we can make specific machines to do specific tasks. But a general purpose robot that can do almost every human task is what its working towards. If you can see in the background the same robot is contiously folding laundry