Piracy has always been stealingᵢ. Violently. Using ships, or boatsᵢᵢ.
What you're calling “piracy” — falling into the “intellectual property” mafia's trap by borrowing their malicious misnomer — is just plain old sharing.
Copying what we like (sometimes changing and adding our own ideas to it) and sharing it with other people, so they can like, share, and change it too.
It's how human culture works and has always worked!
Copyright (another intentional misnomer, since all it does is restrict the right to copy — and share, and modify — cultural works) is, at least in its current form, not only detrimental to culture (and its spread and preservation) but an attack on human nature itself.
Sharing, in these dark times when destroying cultural works seems to have somehow become more profitable than commercialising themᵢᵥ, has become not only an essential part of human nature, but a moral imperative for anyone who cares about art, culture, and social progress.
As for the hypothetical profits we are supposedly “stealing”, paraphrasing Neil Gaiman, sharing not only doesn't cause a loss on profits, it increases themᵥ. It's free advertising.
It's not about profits. It's not about authors' rights. It's never been. It is, and has always been, about control. About deciding who and when can have access to culture, and who can't. When we can be human, and when we are not allowed to.
I — Well, sometimes mostly murdering, I suppose, if there was not enough to steal; and of course there was the whole letters of marque thing, which made it political and complicated. But mostly stealing, OK?
II — It being on navigable water is what distinguishes it from pillaging, if I'm not mistaken.
III — In the borrowed words of Sir Terry Pratchettᵥᵢ, “The anthropologists got it wrong when they named our species Homo sapiens ('wise man'). In any case it's an arrogant and bigheaded thing to say, wisdom being one of our least evident features. In reality, we are Pan narrans, the storytelling chimpanzee.”; sharing stories, and any other form of culture, is what distinguishes us from other species. It's what makes us human.
IV — And even before. “IP” wranglers have a long history of not being reliable custodians of the cultural works they claim responsibility for, and sharing has many times been the only way to preserve said works after their (often malicious) mismanagement.
V — There's studies, too, if Gaiman's account is too anecdotal for your liking.
VI — GNU
When copyright holders can remove access to paid content on a whim, or destroy already finished works because it's somehow more profitable than selling them, or simply don't care about preserving the works they claim to be responsible for, archiving them even against their wishes is not only moral, but a moral imperative.
Culture is more important than profits. And if preserving culture is illegal, the law is wrong, and must be ignored until it's been corrected.