Well if a group of the poly persuasion suddenly got together and took over the world, forcing the others to adapt to their lifestyle, yes, it WOULD be horrid, as none of the 'normals' would be ABLE to adapt, emotionally. Feelings would be hurt, jealousy would thrive, and relationships would be shattered. Thus, it would negate the whole concept of 'sharing the love', as the current culture tends to think of love as a finite resource. Personally, I think it's well worth it, but I'm the sort of person who could be perfectly happy sharing their life with 4 or 5 people, not just one or two.