Excellent point. I knew people who had Netflix accounts and every time a new DVD arrived in the mail, they copied it and added it to their DVD library.
Them: "Check this out, I have 200 DVDs sitting on my shelf!"
Me: "Wow, you've seen all of these movies?"
Them: "No, but they're here if I ever want to."
Four years later, 99% of their copied DVD collections are still sitting there on the self, never watched.
Piracy quickly turns into digital hoarding. Back in the days of the original Napster, people used to download gigabytes worth of music that they never, ever listened to. It became an addiction. The music didn't matter, it was the thrill of the hunt and the sense of accomplishment of having every song ever released. The same goes for copying DVDs, copying disc-based games, and downloading ROMs.
Wikipedia - Digital Hoarding