A lot of geeks are under the misapprehension that the studios don't know this. But actually they are not idiots, they are fully aware of the sisyphean nature and ultimate futility of DRM.
The point of enforcing DRM is not to prevent piracy, but rather to flex their market clout and demonstrate control. As long as they put up moderate barriers to ripping, and as long as they have legal sanction to suppress productized piracy, the steady stream of new must-have content allows them to throw their weight around. Licensing streaming without DRM is a slippery slope that decreases the perceived value of their content. Small distributors will do it because they need to make whatever money they can, big distributors will never do it because it damages their brand.
The point of enforcing DRM is not to prevent piracy, but rather to flex their market clout and demonstrate control. As long as they put up moderate barriers to ripping, and as long as they have legal sanction to suppress productized piracy, the steady stream of new must-have content allows them to throw their weight around. Licensing streaming without DRM is a slippery slope that decreases the perceived value of their content. Small distributors will do it because they need to make whatever money they can, big distributors will never do it because it damages their brand.