You are so right, Steady. I equate this with couples who think having a baby will solve their issues, when it really is a way to avoid the issues altogether. Even for couples who are rock solid and secure, poly is not an easy lifestyle choice. Like any relationship, it takes lots and lots of work, and it takes each partner's effort. If one partner decides not to put in the work it takes to succeed, the relationship will ultimately fail.
Poly is not something you decide to do on a whim. It takes many, many, MANY intense disscussions to assure that it is something that both partners and any potential partners truly want. Even when you think you have covered every conceivable issue beforehand, there is always the curveball life will throw at you (health issues are a prime example, and one I can speak about from experience).
While I support poly 100%, I will always warn anyone who is contemplating poly living to take Steady's advice to heart. You can't have a successful poly union if you don't already have a successful monogamous one. Successful poly families are the exception, not the rule. The failure rate is high, mostly because those involved are not keeping anchored in reality (I call it the rainbows and lollipop syndrome). ANY relationship can fall victim to this. When relationships start, it is a surge of hormones that give us that "high on love" feeling that we think will last forever. Then when the high wears off, many are not willing to do the work necessary to sustain the relationship.
Don't get me wrong--the high of new love is a wonderful feeling. But relationships that you cultivate to grow the deeper love that comes with trust, respect, and companionship are the real deal.