Apple and Amazon managed to change the practices of the music industry because they had enough power. Netflix has started down the path of building more power, by having their own content. Perhaps when Netflix has enough power they can push back on the video industry.
At least in public, Netflix has claimed that they don't want DRM themselves, and would remove it if they could, but that their content providers require it.
Actually, I think the main reason that music went DRM free was to circumvent Apple's dominance. Since they had by far the most popular portable digital music platform, and wouldn't allow third party DRM on it, the music industry had a choice -- either deal with Apple, or forego DRM altogether.
That's basically what happened. Apple wanted to go DRM-free (see Steve Job's Thoughts on Music letter) and did so as soon as they were able according to their contracts. But before they did, the publishers offered DRM-free music to Amazon first allowing them a head start on Apple.
I think DRM is mostly forced upon Netflix by Hollywood. If Netflix didn't need to DRM every stream, they could reduce their hosting costs and network latency by pushing static video content to CDNs and caching servers. For example, Google hosts YouTube server appliances in ISPs to reduce latency.
While removing DRM would certainly help Netflix, it doesn't stop them from offering such edge boxes already; ISPs can already host a box on their network that supplies Netflix videos to that ISP's customers.
At least in public, Netflix has claimed that they don't want DRM themselves, and would remove it if they could, but that their content providers require it.