When it comes to popular games, you really can't "trust" either. User review sites like metacritic, in particular, tend to get bombed by large groups of people downvoting a game just because they aren't fans, or are fans of another game and want to make it look better. There are comparitively few objective reviews, and they are easily drowned out by the hordes of "0/10 haven't played never will" reviews.
On the other hand, professional reviews are just as biased, except it is one person's opinion compared to a lot of them. I generally find them more reliable though, if just because after a while you get a feeling for the opinions of the various reviewers and can use that as a guidepost.