Why is it bad?
The system is heavily biased towards content having a perfect score of all ratings being 5/5 stars, a mod with a single 1 star review and a single 5 star review will be very very far back in the sorting system while a mod with 2 5 star reviews gets placed near the top.
In the above example you can see how a map with 6; 5/5 ratings is sorted above a map with 10; 5/5 ratings and a single 4/5 review. Not only is this very far from being proper sorting the map sorted above is, objectively by reviews and from a personal review of the content, just terrible.
Now you might say the first 15 maps seem to be properly sorted since they are quite good and popular -> just check the second page, theres an astro clone on there which was even rejected by the astro community since it barely has 220 plays.
It gets worse
Switching to the mod vault
There are some great mods that show up only on the 4th page of highest rated, it is sad to see great mods that need to fight for popularity in a niche market get sorted in such a terrible fashion, mods that deserve more attention get sorted far back while mods like "T1 UNIT HEALTH X100" get sorted higher. See for yourself:
All of these mods are sorted below the following mods:
goes on and on:
How do they sort it?
They use a very complex mathematical equasion called: Binomial proportion confidence interval. This isnt a bad way to sort but the devs did a terrible implementation. A simpler system like (stars * amount of reviews) would work way better.
Have a great day!