There are plenty of 19 pax airliners operating with NO cockpit door, and NO Flight Attendant. What do you propose to do about that? Plus many biz-jet terminals have NO passenger screening, allowing all manner of psychopaths, socio-paths, and manic depressive types to fly all over the world. Personally, I don't think ANYTHING should been done about it, but I'm sure this will keep several (many) pundits awake at night worrying that the sky is about to fall.