i would argue that some folks really don't care about scoring...and understand. are any of you linux geeks? do you mess with open source os'es and applications? any kind of logging, logging in, etc. is generally seen as a big brother imposition, plain old imposition, and general pain in the arse...
it is like gamespy - gotta have a login to browse and play games - any games that require gamespy are games i do not buy and play.
not saying it is a bad thing necessarily, and my unit will prolly participate once we get MP up and running (gotta iron everything out first), but we generally do not like those systems... Steam came out of that kind of thing - marketeers saw that folks would do this minimal login/data capture, then they slowly add more and more to it. Soon you will need a ssl certificate to play some games...!!! (yes, exaggeration - currently - but think about it) You must also understand that some folks just don't like doing it - whatever their reason, so good thing you can do direct ip games.
not a slam or a dig - Kazan has done an excellent job replicating/replacing the PXO system to bring MP back to the game (do you need a mirror/failover for the service Kazan?).