Scores are marked by normal real people. the users of most ultra high performance tires do not buy and rate ordinary tires.
So the scores are within each rating catagory, and not a universal rating catagory.
Plus ultra high performance users ARE going to be fussier... Than common slob tire users. (slob is my euphemism)
Maybe ordinary folks are way more enthusiastic that the tires they bought roll, and generally work... and last longer than six months...
vs the fussier crazed maniacs who opt for high performance rubber.. those folks probably expect the tires to stick like glue even when in gravel, and turn on a dime even when going 110mph.. (I know that is what I expect) and get mad when the tires only last six weeks instead of six whole months. (all the while they were doing endless burnouts to impress the Saturday Night crowd)
My gripe is the comparos lump all sizes together.. Even though there is a huge difference in behavior of a 15" 60 aspect vs a 18" 40 aspect tire. Same name and brand, but those two sizes are totally different and i doubt any characteristic noted by a user of one would apply to the other except tread design.
One help would be for user reviews to include the complete size info they actually owed.
Like "my GummyBear wumpstepper Fg6 were 215/50/17 size...." etc.
Also the issue of comparing all season to snow in the snow ratings of light snow, heavy snow and ice. The best all season have very close to equal ratings as snow tires.. Yet all agree snow tires are way better in those areas.. So it is obvious the ratings do not cross the type of tire barriers.