Thing is, I have a different opinion, but I've also experienced heartbreak. It is actually possible to be polyamorous, and experience heartbreak. Actually, you are setting yourself up for potential of much more heartbreak, then when you are monogamous.
But also, you are setting yourself for a lot more interesting, meaningful and nice relationships, that have lower heartbreak chance overal.
Why? Because polyamory is first of all not about banging people left and right. It is about ethical relationships. A good idea for non polyamorous people would be to take a look, and perhaps borrow that page from polyplaybook. It might make your relationship happier overall.