Have we not heard of simpler is better? Because, you know, mono people can get away with not communicating and lying and cheating and still have a successful relationship! We ever-so-evolved poly people need to actually put effort into our relationships while our less-evolved brethren have a walk in the park. No need to communicate or compromise there! We take on these extra hardships in the name of science!
Oh, and mind reading is the best skill to have ever! It means we can skip those pesky communication and honesty parts in favor of guessing games! Whooooo hooooo!