From the article:
When we went to our seats, the wait staff let us know that despite the fact that the previews were playing, we wouldn’t know until the movie actually started whether we could see the film or not. If it didn’t work, the screen would just turn black. Luckily, the film went through without a hitch.
Someone working in a movie theater could just take the file and send it to other movie theaters and then they can play the movie whenever they want without paying the distributor. They could also just upload it onto the internet so anyone can watch it. It’s essentially to keep theater operators honest.
Except people can do those things anyway so the DRM is all just creating problems for the honest ones.
Yes I’m aware but if the DRM wasn’t there it would certainly be easier