I don't know why Wigderson can't read,* I only know that he wasn't able to read in at least one instance. Because if a person makes a certain claim but another person does not make that claim, then the person who did not make the claim has not "joined" the one who did.
Seems straightforward enough to me. As a matter of fact, this source did not even make the claim. So Wigderson is fantasizing.
Whatever turns him on, as they say.
* His blog post is entitled, "How to be complete morons," which is considerably more effective as a descriptive label than as advice.