I think what he meant was those who play games per household. Not aiming at casuals or hardcore gamers. Just the fact that they play games.

But for the purpose of the study it was appropriate.

I think that was kind of the point the author was going for. Ultimately when trying to prove a point you go with information that benefits your point best. He could've done it your way and decided to not use that information because it didn't support his point as well as what he used.

Welcome to politics.

Same difference because they use the same method. You're not going to make a study that does not support what you are saying. It all devolves into politics. Facts are always twisted to best suit the user. you would be hard pressed to find something that did not have twisted facts. Perhaps I should've said something different but point remains the same.