> If you accept a trial's outcome that the accused is guilty, it follows logically that they deserve to be punished more for denying it (or at least, more than they would be punished if they confessed.)

No, it doesn't; it seems illogical, I would say, to impose additional punishment for people asserting their Constitutional right to compel the government to prove criminal allegations beyond a reasonable doubt without relying on testimony provided by the accused. It is contrary to the entire idea of a Constitutional right.