That's not the question. The question is why Mr. Bernanke wants it not to be money. That's not really a question either, but I digress.
Another question is why you are claiming that Bernanke doesn't want gold to be money, when he never said that. All he said is that gold is not money. Neither is salt. It has been and it could be, but it currently isn't. Your assumption is probably right though, I don't think he wants gold to be money either. The reason is that it has been tried, and found to create a lot of problems that fiat doesn't have. Some would prefer those problems over those fiat creates, either because they think they are smaller, or because they pretend they aren't actually problems. They are apparently a minority in practically every part of the world, though.