There is zero harm to others downstream, because the only thing those people are being deprived of is a product that wouldn't exist at all without the "evil" content creators. You're not being deprived of anything when you can't download Avengers: Infinity Wars for free. You're just prevented from having your cake and eating it too. (I.e. consuming a product that was created in express reliance on the copyright system, without paying for it.) Which is the reason we allow companies to enforce this artificial scarcity--it allows creation of a product that people want more than the alternatives.
It's precisely because this scarcity is artificial that it's moral. If people wanted to consume content from "open source collaboration or hobbyists" then they would do it. Nothing is stopping them. But people don't want the hobbyist project, they want the $200 million Hollywood blockbuster. And if that's the case, people have no right to demand access to that content on terms different from what the creator is willing to agree to.