We already did at huge length. That you didn't bother to read it doesn't mean we need to repeat it for you. No-one else is claiming this. It's one thing to disagree, it's another thing to claim no-one has explained to you.
There have been literally thousand of posts. Believe it or not, I haven't read every one. The only thing I've seen stated repeatedly is that WOTC wants to destroy 3PP and that they've shown that they're basically the second coming of Hitler. Yet nobody explains why, they just jump to the conclusion that WOTC will give a **** and shut you down if you publish a mod.
Yes, they can change the contract with 30 days notice. If they can get revoke the 1.0a version (that's up to the courts to decide) they can revoke any version. They can, in theory, shut anyone down. It would not be in their best interest to do so outside of extreme examples like a NuTSR. Old content is not going to be removed, people would still have a grace period of 6 months to wrap things up and publish under 1.0a, they just won't be able to use the 1.0a in the future. They've always been able to copy the majority of things published and they have not so there's no reason to believe they will in the future.
See? That wasn't hard. An entire paragraph. Phew. My fingers are about ready to fall off! I'm not saying I support the decision, I think it was a mistake. I also don't think WOTC is putting the bootheel of the corporation on the throats of every individual who publishes material either.
If you're just going to respond "You're wrong!" don't bother.