I was the person that pointed that out to you on Reddit. They do have ratings on user feeds after you've played the game, but that's only if people have an account. Other than that there is no way to rate a game in the client and that's what I use. Its a pain having to search out the page to rate.
As for me I've got 6 ratings on a game with 120 downloads (1 rating is from a friend). The other game has 300+ downloads and 2 ratings.
Also having my name tied to a rating makes me far less likely to rate a game unless its 5 stars. At that point I'd rather comment to hopefully encourage a product to be enhanced.