Efficiency has become a measuring stick all it's own. And while I am not against alternative statistics, when they take on a life of their own they start to lose relation to the point of playing competitive games. To win.
The same argument for efficiency is the same strange one you are starting to hear in baseball about WAR. When they don't match up to what we see in the win columns, the stat heads start to move to the argument that maybe winning and losing is not the best measurement of who is actually the better team.