If you don’t hold by kitniyuos to begin with, you aren’t part of the discussion. For you, quinoia, maize (corn), rice and beans are all acceptable on Pesach. The debate isn’t whether one may eat quinoa per se (since it clearly is not hametz), or whether one may eat kitniyos (that’s a different issue), but whether qinoia is kitniyos?
cherrybim: If being “new” is the deciding factor, do you eat maize (American corn) which also was introduced to Jews after the initial bans on kitniyos.