I don't know if this is a valid answer to that problem, but I think the idea that we need to rate games is a flawed concept. Movie reviews are a lot more than the number of stars under the movie's name - they're an indication of what the critic thought, felt or perceived as he was watching it. It's no different for a game.
People bashing reviewers and review sites because they dare to give an 8 probably are the sort of consumers who scroll straight down to the review score, because honestly, EVERYTHING deserves a TL;DR these days, because people can't be fucking bothered to fucking read, anymore.
So they see an 8 out of 10, reflect that on their own enjoyment or hatred for a given project and if both don't match up based on lacking data, then they fly into a rage. the "h8ters", to coin a phrase, are just as unnerving as folks who wander into a Skyrim topic (or any other game-related topic for that matter) and just drop "This game sucks!" or a variation on it - without making the least bit of effort at articulating their claim.
To these folks, I'd like to say that you need to brush up on your understanding and definition of games journalism, journalism in general, the art of criticism as well as your ability to get a clue, for once. Journalism does involve a fair share of statements of opinion, of course, but it's a lot more than just another soapbox we're giving to people that are randomly paid to state how much they hate or like a given product.
Journalism implies investigation. If you're going to say that a given game's set of mechanics feels unconvincing, then you should be able to explain why, and not just say that it's crap and move on. In comparison, hating a reviewer or a reviews site for a given score is pretty much the equivalent of hollering an uninformed opinion at the top of your lungs.
Look, we get it. The Internet is a wonderful place that favours self-expression and independent thought. The key word here is "thought". Going out on a limb and raging against a reviewer does not equal thought.
Considering all that, we'd probably be better off nipping the problem in the bud and eliminating grades altogether. As reading the entire review is conducive to understanding the purpose and thought process of the reviewer, that's a lot less likely to leave room for sudden unfounded flames. Any site could eliminate scores for a while to test the waters, then reintroduce them a year or two later - largely to see if this gives more worth to the now fairly commonplace and misunderstood 8, 9 and 10 scores.
In the best of worlds, 5 would still be understood as being the mark of an average game. It also means we'd have a lot more 5-scores around than we do now. Anything upwards of 5 would be the mark of something that goes from being above the call of duty to being exceptional. Ideally, perfect scores would be completely weeded out of the equation.
Let's face it. Nothing ever made by human hands could ever be considered perfect. Even Da Vinci would still be tweaking the Mona Lisa, if he could.