To get more players, id needs to restructure the system. Whoever designed it must have never played any kind of sports, and also never studied or heard of sports psychology. Let me explain it simply for the id software engineers:

Players do not like to lose reputation. If they lose games under an alias, they don't lose reputation. That means, if players can be anonymous, they are more likely to play. Forcing people to have a static identity is one of the most game-killing things you could possibly do. We have never, in the history of Quake, Doom, Wolfenstein or anything else, had a problem with people using aliases or playing anonymously. If it ain't broke, don't fix it.

The solution is easy: separate match-stats from practice-stats, and let people play anonymously. The latter of these things means, statistics are not kept and aliases can be used freely.