Can Co-Op Boards reject buyers without giving a reason? Does this apply if there is discrimination?

Technically a co-op is not real property. You are purchasing shares of the company and they can do what they want. I feel that is the main reason why co-ops exists; to control the types of people who live live in the building. As a fellow New Yorker I have seen this type of thing happen all the time. My fiancee's aunt in uncle were trying to sell their co-op for 2 years because the board did not approve the potential buyers. Some co-op boards are better than others though.