It's not about literally proving that piracy is morally correct - it's about getting your average person to rethink their gut reaction to the idea of piracy. It's the same as pointing out how it's estimated that more than 50% of all games are now lost forever because the companies who made them never bothered to keep the source code. Or how many early BBC recordings only exist because of people who taped them at home and sent copies to them after a public request campaign because the BBC reused the tape reels for newer programming over the years.

The more people who reconsider their first opinion of piracy as a bad thing, the more people who support it and actively participate in that kind of preservation there will be.