Engaging in proliferating an unethical practice under pretense that "they have no choice" is a very questionable thing. Netflix had a choice, but they chose to do this.
They could exist trying to concentrate on DRM-free distribution. Others managed that: https://www.headweb.com/en/
Of course it wouldn't have the same scale. But we aren't talking about scale - you mentioned existence as if selling something DRM-free is not possible or not sustainable.
The profit that comes from actually having content to offer, which wouldn't happen if they didn't have DRM to "protect" the studios' shows and films.
Regardless of their opinions on DRM, it's not their decision to make, unless they just want to stream self-produced content.