If pirating were at least as convenient as buying, then sure. But pirating is a lot of trouble. You have to have custom software that serves no other purpose than this. You may have to hunt for codecs. You have to make sure you're getting the right thing. If it's a foreign film (90% of what I view) you have to dig around for subtitles which are often very poorly written and/or don't sync with the film properly.

Pirating is a pain and I think most people would pay something to avoid having to do it. The question is just how much and how convenient it is to do so.