Not just that, there is the not so minor issue of speed. Notice there was the "if they are as fast as traditional computers" qualifier. How fast will we be able to make quantum computers? Who knows at this point? It is possible that they'll end up being something we can realize, program, and use, but despite the advantages they have at solving certain kinds of problems they are dog slow compared to traditional machines.That was my first thought as well. The head of IBM Research saying something as stupid and fantastic as "quantum computing will break it." Does this guy just drink, snort cocaine, and drive a car with doors that "do this?"
Commercially available quantum computing may only be a few years out, but the amount of architecture design required to feed and interpret the needs of a a quantum platform are _still_ in the theory phases. We need a new type of memory/FPGA hybrid before we can even start thinking of programming for such a device.
There is just so much we don't know right now. It would be like trying to predict where computers would be today back in in 1941 when they built the first opamp. We really don't know where quantum computing will go or how long it'll take to get there.