You're entirely, totally wrong. As my writeup, the publishers' summary, and many reviews around the web make clear, he played many, many characters, in many games, for decades. He went to many gaming cons. He sat in on a session DM'ed by Ernie Gygax, who played the first-ever D&D game, with his dad Gary. He LARPed.
Honestly, I could see being concerned that this might be the case, but I can't see publicly opining that it "probably" is, when a moment's -- a half-moment's! -- research would have shown otherwise. It's pretty poor, really.