Hollywood has no desire to enter an open platform. They're completely happy if none of their movies are online, ever. Really. They already have a massively profitable distribution system in the theaters.
The problem is that people want to watch Hollywood movies on their computer, including people that use Linux. So what do you tell those people to do? Tell them run Windows? Have them go watch it in the theater? And they have copyright controls that can force offline sites that host copyrighted content in various countries.
So DRM is the tech industry's way to kiss these people ass. It may be flawed or may not work, but it's still ass-kissing. They're the artists, they get to decide what they do with their art. The consumer has no right to an artists creation. Their only choice is to pay up or ignore it.
And you'll find that this happens to other art mediums as well. There are many, many art galleries that won't sell certain works of art if they deem your ownership as insufficient. Literally - the customer is wrong.