It's not about being good, it's more about them being able to show me that they know what they're talking about. Isn't that what someone who goes to their site for impressions/opinions on whether to purchase a game or not wants? When you see some of them struggle with certain games in quick looks or whatever, you can't help but question their final opinions on the game.
Look at Brad and his opinions on raid mode in Revelations in this thread. He thinks the gameplay is lacking to warrant going back and playing raid mode, but the core gameplay of the game is the same as RE4/5 and in essence better due to the control scheme. Not to mention raid mode is more of a co-op based mode, and I have a serious doubt he set up some online co-op with someone and played raid mode for at least 4 hours before brushing it off. The comment someone made earlier in this thread, that he "only reviewed half of the game" is most likely right. Even if he says he played it, his review makes it seem like he loaded it up, played a level, and said that's enough for me. Well, that's not much of a review. Of course if this assumption is false, he should word it better in his review. Everything in the raid mode section I could easily ascertain from the game's manual. This leads me to believe Brad simply wasn't good enough at the gameplay to appreciate a mode like raid since it requires more skill than the main campaign to obtain high scores. Again, if I'm wrong, great, but that's the impression the review gives.