First off, I think people go off the reviews to let them narrow down the selection of vehicles that they will go out and try themselves.Thats exactly it. Most people don't read car blogs and that demo relies on CR and edmunds. I find it slightly scary actually how many people actually farm their decisions out to subjective reviews (subjective being not YOUR opinion as the person spending the money)
Second, I think that these reviewers are subjective, but give value in that they are very well informed and knowledgeable about the car industry generally. Having more knowledge of history, competitive vehicles, mechanics, etc... allows them to give more insightful critiques of vehicles than the average person can.