The DRM approach to piracy is an all or nothing thing. Once one person cracks a DRM setup they can distribute any movie protected by that setup to as many people as they want in whatever medium they want.

I think propagandizing piracy has had a lot more to do with its decline than ease of use. Try using popcorn time. It is incredibly easy.

I don't even know that this is true. In my personal experience (so completely anecdotal), pirated content is always much easier to ingest than paid, DRM'd content. There hasn't ever been a single DRM system that actually made piracy more difficult. If anything, it just made usage for legitimate users difficult. The only exception that I can think of were the DRM systems for video games that existed (and some still do) where it takes them a week or 2 to crack the DRM. Even then, the people that weren't going to pay for those games just wait until the DRM is cracked. It didn't actually make pirating the games harder, it just made it inconvenient for a little while longer but that's never been shown to equate to more paying customers.

  Easy piracy destroyed the music industry.

While not exactly false, this statement bears too much of a negative connotation. I'd rephrased it as "Easy sharing of digitized content forced the restructuring of content-distribution industries" or something like that.