I think he's talking about AAA singleplayer games - and not singleplayer games in general.

I think he's somewhat shortsighted, like most people.

Traditional "AAA" games are likely moving primarily to multiplayer, that's true. But there will always be a significant market for singleplayer games - and I have no doubt that there's room for big budget versions. AAA is not the only way to make a "big-budget" game - and there's a middle ground.