Perhaps the American judges are trying to protect some power they believe belongs to them? As I read it, the Constitution puts the power - the determination of guilt/innocence before the law - in the jury, otherwise every trial would be a bench trial.
Exactly! Moreoever, the state may not prosecute a person for a crime unless the grand jury agrees -- the person is shielded from direct action by the state by a panel of his neighbors, and can be tried for a crime only if they agree. And then another jury, the petit jury, will ascertain the facts and law of the case, and determine guilt or innocence. Plus there is a presumption of innocence until/unless guilt has been demonstrated to the jury's satisfaction.
Ours is such an amazing system! I can't imagine a system of justice superior to our own. In most of Europe -- excepting Great Britain, of course -- the defendent is presumed guilty unless/until proven innocent; and judges, not juries, make that determination.
I though it very interesting that Mahatmas Gandhi abolished the jury system -- a fixture of the British Empire -- when India gained her independence back in the late 1940s IIRC. I asked an Indian friend why India decided to shuck the jury system. She told me it had been rife with corruption. I didn't say anything, for I didn't want to be impolite. But speaking for myself, I would rather take my chances with "corrupt" neighbors than "corrupt" judges, any day....