This exact mindset is partially the reason why game reviews have this annoying "goodwill" system which causes every AAA sequel -- unless it really fucks up -- to get 90%+ scores almost regardless of flaws or changing standards or repetition. From the moment Halo was released, Halos 2, 3, 4, ... have been guaranteed 90%+ scores. From the moment Uncharted 2 shocked everyone, Uncharteds 3, 4, ... have been guaranteed 90%+ scores. Same with Zelda, main Mario games, and so on. Reviews of AAA games have about as much to do with quality as they do with preconceived notions of the particular series.
The video game press is largely drive by hype and reputation. It's annoying as hell.