It's hard to generalize, but often it's really just a few whales propping the whole thing up.

While they may make up 2% of the users, they can account for 50% to an astounding 70% of game developers’ profits

The linked article is referencing Candy Crush, not AAA games, but it's hard to find published data on the matter. Different games and communities will be different, but I would hesitate to broadly blame consumers for this.