He didn't tell anyone not to post. He requested that a person refrain from posting. And if someone who can't write a correct sentence can't tell others what to write or not write, then doesn't your own run-on sentence disqualify you from telling him he can't tell others what to write?
One of the reasons it is foolish to criticize the grammar, syntax, spelling, punctuation or prose of others is that almost invariably such criticisms are overflowing with errors of their own.