Because these people often don't want to pirate. In Germany the government now fines you for piracy, using a common VPN isn't enough anymore. Then there are other factors such as remasters and changes.
Fight Club, The Matrix, The Terminator and Star Wars are all popular films but there are several versions out there with different color grades and special effects. So I completely understand why this subset of people would want to keep their version of the movie.
And that's exactly why your kid will never make lieutenant.