I actually think in general Joe is pretty accurate in his reviews
sometimes its obvious he's overrating certain games because of some sort of influence (hint hint bribes) but even in circumstances where he seems to overrate a game (Dragon Age Inquisition) he makes sure to mention plenty of flaws and issues in his reviews
he is one of the most comprehensive reviewers around in terms of mentioning the good and bad points
the reality is no one buys a Halo game for the its campaign anyway, but obviously its disappointing for it to be short