I'm still waiting for the explanation of how it actually causes harm. Most of what you describe is not exactly harmful and is easily dealt with.
What's to stop someone from creating their own web client that doesn't implement that part of the standard? Where's it written that we have to follow every bit of the standard as it is written? Who gave this select group of people that much power over the open web?
Personally, I think the W3C was approaching being corrupted long before this issue. Maybe not in the terms you are describing right now but I've had issues with the behavior of various standard bodies and browser providers that happen to be a part of these bodies for a while now.
As for artifacts of culture being locked away from future generations, that is a potential problem. But we all know a silly DRM scheme isn't going to stop that. But that kind of thing has been in practice for a long time, way before we had electronics and the human race seems to be moving along in despite.
To me, a better solution is to show that people are willing to move on from these aspects of culture that everyone is so hung up on. If enough people show that these schemes don't work in the long run the content providers are more apt to change their ways. Look at the music industry, it's vastly different than it was just a few years ago and continues to change. Let these people attempt their schemes, in the long run it will matter little.