A couple of sore points. I'm a little bothered seeing monogamy and unrealistic expectations cited as the reason for cheating. While being unhappy is certainly a factor, I don't believe it's a direct cause. People could choose to handle their unhappiness differently, ala expressing their feelings or seeking to end the monogamous relationship. Monogamy does not MAKE people cheat.
Also, there was a statement comparing how monogamy is actually practiced (not how it should be) vs how polyamory is supposed to work. That's seems a bit unfair, matching the reality vs the ideal. Either monogamy or polyamory can be a healthy situation if done right. And we've all seen either mono or poly become big flaming balls of screwup when done badly. Again, that doesn't make either suck more or less.
Also, I'm the mono husband of a poly wife, FWIW.