Well, it's his opinion. He didn't make any implications about anyone who disagrees with him. Just as he can doubt the validity of the numerous GOTY awards that The Last of Us received, you can doubt the validity of his opinion. I don't see what's the problem.
And there is a serious problem with the argumentum ad populum argument that you used. The game market is much larger than it was when the gems of the SNES/PS1. Video game journalism was small then, and almost eclusively in print. You couldn't win 200+ GOTY awards simply becuase there weren't that many publications to gave them out (also considering that GOTY tradition was less developed back then). And there is also the problem of argument ad populum itself - that even though the majority opinion suggests that it is more likely that they are right, there is no logical proof. He can doubt it if he presents arguments, which you never asked him to do.