How does Societal "demands " on "true" honesty (vs what false honesty) in either relationship style (Mono or poly) or any relationship for that matter ...family,friend, business, etc have to do with how selfish and bad choices are made.
Stupid selfish people ...(poly or not ) ...no matter what the poly doctrine demands..... will do dishonest and bad things. Read the forum.
Your root cause is the fence. Other see the root cause as the moral compass.