Currently there is a shortage on most of the Rolex professional models with almost all of them being hard to get. For Rolex collectors it's causing many to be content with their collections or to look elsewhere such as other brands. Rolex has intentionally throttled back their distribution of the professional line leaving many of their retailers with empty display cases with the exception of precious metal models, two tone models, and more dressy models such as the Just Dates, Oyster Perpetuals, Air Kings, Day Dates, etc. The less sought after professional models such as the Milgauss, Yachtmaster, and Explorer seem to be readily available as well.
Since Rolex is a non-profit they don't pay taxes. They aren't motivated by profit like the rest of the industry. They are part of the Wilsdorf Foundation. The reduced output is aimed at controlling the gray market from what's been said.