Quality is completely based on perspective.
I could say World of Warcraft is the highest quality game in the world, and I would be right.
Another could say World of Warcraft has the worst quality of any game, and they would be right.
But only to themselves, not to other people.
To me World of Warcraft has a vast amount of game play, I have invested over 200 days over a few years and I haven't even come close to doing all I could do in the game. Other people could do all they would ever want to do in the game in just a month and either be happy with it or think of it as sucky. All perspective based.