My point is that even if we can't prove the D-Wave Two is faster at any problem than a traditional computer that the massive amount of knowledge gained about quantum computers will outweigh the costs.

It's far too early to worry about a non-zero probability of it not working, just like fusion power. All it takes is one breakthrough and a revolution in computing will begin. Doing research on quantum computers is a low-risk and high-reward situation. None of these companies are betting everything on quantum computers.