As I said earlier, if these games are being assigned numerical values, which people place heavy reliance on with regard to their purchasing habits, then it should make sense.
Reviewers using a rating system should lay out what they emphasize as most important and least important. If there are four categories, for example, that a reviewer considers most important and as qualifiers in a final score, then these categories should each be assigned their own values to demonstrate how they're valued.
With that said, it's clear many of these reviewers lament how the game plays or its lack of interactivity (or so they say). Therefore, consider the following example:
On a scale from 1 - 10
Gameplay (40%): 6 (or 16/40)
Visuals (20%): 10 (or 10/10)
Sound (15%): 8 (or 12/15)
Story (15%): 5 (or 7.5/15)
Final Score: 45.5
If I was informed that this was the rationale behind the rating systems for some reviewers, it would make more sense to me since clearly certain aspects of a game are considered more important to them than others (as with gameplay above, for the sake of an example). If not, then get rid of scoring entirely. This would help those who only look at scores understand the differences between their own values and a reviewer's values and adjust for themselves based on what is more important (gameplay, visuals, sound, story, or whatever other category one can mention).
Edit: Using an adjusted version of the above example to match my own criteria, it would look something like this:
On a scale from 1 - 10
Gameplay (25%): 6 (or 15/25)
Visuals (20%): 10 (or 20/20)
Sound (30%): 8 (or 24/30)
Story (25%): 5 (or 12.5/25)
Final Score: 71.5