You're wrong. I assure you, I know this stuff. If the owner can't demonstrate harm, they have no case. "The other three factors" don't cause harm to the owner, so they have no case.

You can't successfully bring a tort case (which copyright infringement is) if you can't demonstrate harm.

> I assure you, I know this stuff

Where did you go to law school, exactly?

Copyright infringement is not tort. Copyright infringement is a creature of federal law, not common law like tort is. And copyright owners can claim statutory damages of up to $150,000 per work in lieu of actual damages at their election. See 17 U.S. 504(c).

And fair use is a defense to a prima facie copyright infringement claim.

Copyright infringement is a statutory tort. But you're right the law makes the infringement itself a violation. And fair use is just a defense.