Most entertainment companies accept the current flash based solutions as sufficient. In this case they are trying to bring html5 to te same level as flash.
I'm pretty sure something similar to Adobe Access can be implemented for html 5 without requiring us to close source browsers, or patent them. I fail to see why you think otherwise.
That aside, not having DRM for html5 would likely do more harm to the open web than not doing it. Take ABC for example, they only let you view their content through flash or through a native app. This hurts the open web more than giving them DRM in html5.
They are already closing the "analog loophole" everywhere else with HDCP and DRM enabled theater projectors, it's pretty clear that's where "content owners" want to be.