I don't think most poly people advocate for cheating (which is what you're doing here). You also make it sound like people are being "tricked" by society into not liking it when they find their partner is cheating on them, when that's the most natural and human response you can expect when you find out you've been deceived at the highest levels.

The only way having multiple partners is ethical is if they are all aware of each other and it was agreed upon before hand that the relationship is open. What you're advocating for is extremely unethical.