Yeah, someone is really unclear on the whole concept of semi-joking-metrics (to quote The Economist, "Burgernomics was never intended as a precise gauge of currency misalignment, merely a tool to make exchange-rate theory more digestible." - I'm sure pun intended).
If you look at the "Big Mac index" almost every country is now considered "vastly undervalued". So while it may be fun, it's basically a teaching tool and not reality.
Though I *do* think the index shows McDonalds may not necessarily be adjusting pricing... it depends on how they source their raw materials, cost of labor, and just plain what the market will bear.
(If you want to see a *really* good example of how there is no reason to think US companies have to match their pricing to currency valuation - go look at drug prices by country...)