Maybe this is why it is not so great for a dojo to be topheavy? Even if new folk come in, they may not learn as effectively, not seeing any peers having similar success and similar struggles. The gap between what they see and what they can do is too big. There is nobody to identify with, no immediately accessible, intermediate role models. And so they don't stick. And I'm thinking this applies to a whole bunch of other dojo social issues, too. Women and training, GLBT training....
There's something to this, I think... Our dojo was lacking in women when I arrived. Not too long after, a very enthusiastic and talented female beginner joined us. Since then we've had both growth in the beginner program generally, and significant growth in the numbers of women. Role models matter, even when neither the model nor the person observing them realizes it.