I think its to do with the leaderboards gimmick. They mentioned something about modded servers being a reason that they didn't want to have ranked dedicated servers, but all in all, if your not in the top 1000 or 10000 you don't really care about leaderboards, and if your a pc gamer (aka the people who made cod get to where they are now) you couldn't give a stuff about the leaderboards. But thats the only reason why I would see them not putting in ranked dedicated servers. I laugh at the unranked dedicated servers idea. If you look on a game server tracker website you will see that mw3 has hardly any non empty servers running.