> Isn't that assumption always taken by default when considering nearly all market actions?

Yes, and bankers are generally motivated by self-interest when undertaking market actions. However, we are not talking about a market action. The question is what motivates Ben Bernanke's decisions as the head of the Fed?

Is he a selfish kleptocrat trying to enrich himself and his buddies, or is he providing prudent guidance to the country and economy as a whole? Personally, I disapprove of his role and distrust the Fed's entirely, so I cannot provide a reasonable answer here.