You are hugely, hugely wrong in the basic premise that actual reality of piracy is something that even comes close to reasoning for people who put these anti consumer practices in.
Use your brain - DRM allows them to increase profits even without piracy (by taking away consumer rights like second sale doctrine and ability to share content with your friends and family). You're seriously implying it's a bit of piracy that's making them say "yes, let's make sure everyone buys their own copy of the movie"? Do you think copyright protection laws were extended to 70 years+death of the authors because there were too many pirates copying Mickey movies?