I know Joseph online outside of YWN. He is perfectly normal. I think he was just rubbed the wrong way here at some point and is out to have some revenge-fun at everyone’s expense.
I did the same thing to a (non-Jewish) forum that was mismanaged. They allowed someone, who actually probably was a high-functioning autistic or mental patient, to blow my cover and violate my anonymity after I had done a lot to help them. I registered phony accounts, purposely posted stuff to give the moderators work to do, created phony drama on the site, started a competing site that I only closed because I was no longer involved in what the forum was about. In the end they imploded on their own and split into 2 forums, both useless.