Sure the body of the review can fill in perspective of how different groups may feel but still, the failure to quantify how that impacts things makes for likely ambiguity. Take the typical Pro/Con most reviews tend to have. Most of the time the number of each is somewhat the same but assuming by number they even each other out would be a mistake. Truthfully just one con could blow out a laundry list of pros. In the end while people may bemoan quantifying their score it is an exercise in accountability. There is no hiding behind "Well, what I meant was". You're putting it out there and as a matter of fact that score can then be put up against others to paint a picture of where the game falls. Now, this is definitely where aggregators fall on their face. Fact is, my critical 6 could make sense when considered against other reviews and another person's 6 could actually be a big anomaly in terms of how they normally see the world. To the aggregator they're all the same though. Some power in the average of 100 reviews but all reviews aren't created equal.
There is no perfect system. I just like the idea of the work being the responsibility of the reviewer. Go to some lengths to make your feelings plain. Take the time to try to put yourself into another perspective to evaluate the game in a different light, accounting for another person's legitimate perspective.
I think the Aerosmith or Sonic game reviews stand as great examples where the qualifiers help. If you give the game a bad review is it because of the game itself, the license, the lack of originality? Even for fans of the band the game could be terrible if the mechanics of the game are poor. Even fans of the music would be entitled to clearly know this rather than just flatly saying fans of the band will pick it up anyway. No, they'll pick it up anyway because nobody would address the shortcomings of the game in a way that fans of the band wouldn't disregard as someone just not liking the band. Again, I liked the game, I just think the situation it falls into illustrates the problem well.
Trust me, as verbose as I am (as you can see), there is easily a part of me that believes that the work a reviewer puts into their choices of words and turns of phrase should be properly appreciated. Writers put nuance into the reviews to be appreciated and people who short-cut to the score can miss a lot of quality points. Hell, the format of reviews for this very site, where the body of the review only is on the first page and numeric scores need to be clicked through to... it is something I collaborated on. Thing is, as a reviewer the job is to serve everyone, even the chronically lazy or just those in a hurry. So there is something to be said for taking the time to crafting consistent and clear condensed views. Having written in real print I can tell you a full review of a game in 250 words or less is a powerful exercise. I enjoy going the other direction (obviously) but perhaps the best test is to put equal time and effort into both. Qualifiers would just be the direct paragraph and score offset guided right to a legitimate audience, doing them a greater service than the "for the masses" review that addresses both everyone and no one.