Mike, I agree that we need to improve existing materials. My point in the blog post is to point out that, like with Free Software development itself, we have proprietary competitors that we have to succeed against, and that these proprietary competitors are entities that people tend to think are on our side. They aren't.
I have spent a lot of my career helping organizations release work as Free Software. I tried the same here, for years, discussing with people at the Linux Foundation, asking them to release their materials under Free licenses. They pretended to be working with me, then stopped talking to me and released even more proprietary materials. I think public pressure can possible have an impact on that behavior, which is why I wrote the blog post.
But I agree with you that we shouldn't spend further time pleading with them. One plea is enough. I've made it. Now let's get to work on copyleft.org. :)