It's funny, I was thinking along similar lines this AM, when running those rough figures.
Students of cryptology will know this story, but it's worth repeating here:
Alan Turing reportedly said something along those lines in the middle of WWII when he was working on cracking Enigma using Colossus and the Bombes. Supposedly he said that if it would take X years to crack a known cypher, but if a new technology would be invented in Y years that would crack the cypher in a fraction of X, and Y was significantly less than X, then you were much better off devoting your time to creating the new technology then you were in doing the straight forward cracking.
So that's Turing and the other heroes of Bletchley Park did, and a lot of the reason we have modern computers is a direct result of that work. It goes without saying that work is also a huge reason that none of us look at Tokyo and Berlin as the co-capitols of Earth.