This is kind of a dumb argument, isn't it?
I have to imagine someone centuries ago probably complained about inventors wasting their time on some dumb printing presses so smart people could write books and newspapers better when they could have been building better farm tools. But could we have developed the tractor when we did if we were still handwriting everything?
Progress supports progress. Teaching computers to recognize and reproduce pictures might seem like a waste to some people, but how do you suppose a computer will someday disassemble a ship if it is not capable of recognizing what the ship is and what holds it together? Modern AI is primitive, but it will eventually lead to autonomous machines that can actually do that work intelligently without blindly following an instruction set, oblivious to whatever might be actually happening around it.