A correction and a thought. There was never 36 boards. There have been 36 board areas designated, and 33 of those areas have seen their residents choose to form a board. The three that don't haves boards all have their own reasons for not. 
When the system was being set up, the Commission that was in charge of it had great debate over who should be eligible to vote and serve on a neighborhood board. One of the choices they made was non-citizens were and are eligible. Interesting in light of the immigration debate going on in our country. Someone shouldn't have to worry about deportation because they want to participate in a neighborhood board. The second debate was if business owners should be allowed to serve or vote. The decision was to have it more like a state or country election and restrict it to people with primary residence in the board's boundaries.  Mr. Dos Santos-tam is correct, business owners are clearly invested in an area and should participate as members of the public.