I had the exact same observation but for another Apple app ecosystem: Game Center. I could not care less how I rank in the global rankings for an iPhone app. Do I care that some 10 kids or idiot savants have scored 100x higher than me? Not really. Maybe if I had actually joined a league or something I would like to know how I ranked globally but otherwise, that's not what you want to show people by default.
There is some pride in knowing that you are one of the 10 best people in the world at the iPhone version of carcassone but that pride gets to be enjoyed by exactly 10 people. Everyone else gets to see their relatively low scores compared to total strangers.