It seems to me that if Rossi announced and confessed to the whole world that he is and always has been a fraudulent con man, there would be a contingent here that was sure this was all just part of Rossi's plan to hide his miraculous pink unicorn perpetual motion machine magic heatilator.
Or, as Mark Twain * put it, it is easier to fool people than to convince them they have been fooled.
(* Attributed, and I believe I saw that in a contemporaneous article in the New York Times.)