The whole concept of “Open Game Content”, which is trying to claim ownership of non-copyrightable game mechanics, is the original root of this issue, and the ORC will probably perpetuate it.

I know this is a take going around, but I think there's a part of the point that it's missing. Publishing stuff under an open license tells people that it's your intention to share the material. Even if everything is already covered, I think having a clarification from the creator of, "This is ok to use, I'm not going to try to sue you over this" is significant. What's happening now is that Wizards is doing something that's probably illegal, but there's just enough ambiguity that they can threaten small creators with expensive legal battles they can't afford, even if they're in the right. Having an explicit statement from the creator that the content is free to use could be helpful in that circumstance, to ensure that there's no ambiguity.