Not entirely, but yes in a way. Reviews are reviews. They're not telling you to jump off a cliff if your favorite game gets a 1 out of 5, 10, or whatever. It's just a guide that tell you what will you expect in this game in a general, unbiased (mostly hard to accomplished that) viewpoint. And half the times, they are quite true.
Lets take Shadow the Hedgehog for an example. SdtH gets a calm score around 6 or lower from most reviewers because the game still has its fair elements from previous 3D Sonic games, but it was crap up with bad gameplay (most running and use of guns), cheesy missions that are heavily boring and/or time consuming, and a story line that has quite horrible voice-acting. And you know what, I played it, and the reviewer wasn't lying one bit of it.
Every game isn't going to be enjoyable to everybody, and reviews are one of those people that can express that and guide people about their experiences with it. Besides, if you know a review is wrong, why bother listening to it? You know it's true that the game is good to you, so why make a commotion about one's opinion that is mostly not true to your view? You'll have to deal with that in the future or you're not going to respect opinions anytime soon.