Many people who review games now prefer to rate games using a four points scale - enthusiastic/love, suggest/like, neutral/indifferent, avoid/not for me, as opposed to giving a score out of ten, or a number of stars out of five. I guess this four point scale is something that is clean and direct. You don't need to argue about the definition of what a 7 is and how it is different from an 8. However I don't think it is much more useful than a 10-point scale.
When I see the BGG rating of a game, or it's rank, what it tells me is how much the average BGG user likes this game and how well it is liked compare to other games. Now this concept of an average BGG user is abstract. There is no such real person. If my gaming tastes are close to this BGG average, then I will probably like a highly ranked game on BGG. So the BGG rating and ranking can be tools to guide me on what games I should explore. The drawback is I usually won't bother to check out games ranked beyond 300, or games with a rating below 7. This is despite the fact that there are games that I like which are outside of these thresholds. In this sense, the BGG ratings and rankings does me harm.
Average ratings and rankings consolidate inputs from many people. When a single game reviewer shares his (or her) rating for a game in his review, this is data from just one person. How useful would this information be? It depends on how closely your tastes match this reviewer's tastes. Do you know how well they match? Do you unconsciously take the rating as a sacred number? Oh this game must suck because this reviewer says so. I have a bad habit of scrolling down to the end of a review to see the rating before deciding whether to read the review itself. Maybe that is a quick way to screen out poor and average games, but I think I have missed some good games because of it too. And there is just no accounting for tastes in the first place. Even if I agree with a reviewer on ten games, there is bound to be an eleventh that our opinions differ.
Some reviewers prefer to list bullets points of pros and cons. I find that a little boring sometimes. After a while all the pros and cons sound like they come out of a checklist of possible tags to attach to a game. Is a game simply a list of strengths and weaknesses? Does everyone have the same standards for what are strengths and what are weaknesses? I think in boardgames one man's meat can be another man's poison. And vice versa, of course. Try to imagine a game that you love. If someone then lists all the weaknesses of this game, you may find that none of them matter to you. But if applied to another game that you dislike, you may find that, yeah, all such weaknesses are true and are stopping you from enjoying this other game. In my case, an example would be the unforgiving nature in Antiquity, and that same unforgiving nature in Greed Incorporated. The same applies to strengths of a game. If there is a game you simply don't like, even if someone can list 10 strengths, they wouldn't move you.
OK, if ratings and rankings have limited usefulness, and can even be harmful, and pros & cons analyses quickly lose meaning, then what is a reviewer to do? I don't have a right answer. I only have an opinion. I prefer reviews that try to capture the feeling and the essence of playing a game. No need to try to describe the mechanisms and rules in detail. No need to have a comprehensive summary of all key features, as if any omission is a failure. No need to come up with a weakness if you don't feel there is any that bothers you. The same applies for strengths - there is no need to try to be fair and to acknowledge some redeeming quality in a game you dislike. I like it when a reviewer can capture what is unique about a game. Sometimes it can be some central mechanism that drives a game, which is something very concrete. But sometimes it can be just a general feeling when playing the game, which is more abstract and does not require the game mechanism to be explained in detail. I like it when a reviewer explains why a game captures his imagination, or why a game disgusts him. It is something one can relate to. Sometimes the reason a game is loved by a reviewer is the same reason that I'd avoid a game. And I'd say the review has been informative and useful to me.
Why do you read game reviews? I used to read them to learn about new games that I may be interested to try or to buy. Sometimes I read them to learn more about games I am already interested in. Nowadays I find that I tend to skim them more than I read them. I am buying fewer games than before. I probably get more enjoyment out of reading entertaining gaming anecdotes (which are more fun if they are related to games I already know) than reading information that helps with buying decisions.
To simply measure a game on a good to bad scale, regardless of the number of points on that scale, misses one important consideration - the context of the game being played. E.g. the audience. If you play games with different groups, some games will work with one group but not another. Their gaming tastes, how "hardcore" they are, their ages, their professions, all do matter. I imagine many games will have spectrums of different widths and depths if we try to measure how well they work under different circumstances. Other than people, there is also time of day, energy level of the group, weather, and festive seasons (gambling games for Chinese New Year? Horror games for Halloween?) to consider. Sometimes I ask myself - what game am I in the mood for today? It certainly helps to have a decent collection of games. No matter what kind of mood I am in, as long as it is a mood for playing games, I can always pull something off the shelf that is right for that moment. I guess that's partly why my buying urge has cooled much lately.
Perhaps there are no bad games. There are only bad moments to play a particular game.