My husband and I had an accepted all-cash offer on this unit recently. Our financial and credit standing well-exceeded the building’s requirements - very big income, plenty of assets (liquid, real estate, investments), 800+ credit scores, etc. Our letters were beyond stellar.
Yet, we were rejected - immediately and without explanation or any questions having been asked. Everyone was surprised - the lawyers, the agent, and the seller (who happens to be on the board).
Although one can't be certain, my guess is that they were not comfortable with a gay couple moving into their building. There is really no other explanation.