<<The coin looks terrible. Why would someone do that? It is not a rare date like 1964.>>
Well, it's harder to counterfeit a 90% silver coin, since anyone knowledgeable enough to buy it will scrutinize it a good bit. It actually would make more sense to try to counterfeit a clad than a silver.
Also, a 2012 half dollar is technically more than 100x rarer than a 1964 half. Over 400 million 1964s were minted, versus less than 4 million 2012s. That said, I did find a 2012-p Kennedy in a box yesterday, but I did not find a 1964... Did find a walker, though!