Monogamous marriage matters. As a 21-year veteran of the institution, I can attest to its imperfections. But compared with the alternatives, it looks pretty good as a means of rearing the next generation. It is more compatible with egalitarian, democratic values than polygamy is, and it has various advantages — including sheer economic efficiency — over single-parent child rearing.Of course, he disregards the benefits that non-monogamy can have for creating and sustaining loving and stable families, should that be one's goal. If we had a culture where married people had more leeway to negotiate the sexual rules of their partnership, we'd probably see many more stable and happy marriages. A couple that's trying to stay together for their kids despite their difficulties might find their task considerably easier if they agree that they will drop their insistence on sexual exclusivity.
And if two parents are more economically stable than one, wouldn't three or four be more stable than two? Poly families seem poised to reap the benefits from extended kinship networks that the modern family has largely abandoned. A poly family more closely approximates "It takes a village to raise a child," than most of the nuclear family arrangements we have in modern America.
I'm not saying that polyamorous families are better than monogamous ones, or even attempting to denigrate the dedication of those who cleave closely to monogamous ideals. Dropping monogamy isn't the solution for everyone in a disintegrating marriage, and a triad isn't superior for child raising to a couple. Happy parents are likely to lead to a happy family, and I'm the last person to suggest that someone should attempt a framework for love and sex that goes against what feels most right to them. And I'm certainly not excusing Tiger Woods or adulterers in general, whose behavior, should they not get the okay of their spouse, is dishonest. It's just that any non-monogamous arrangement is held to a higher standard of social benefit than a corresponding monogamous arrangement.
Our chief problem is one of perception. Look again at the above quote- the only options Mr. Wright can conceive of are 1.) adultery, 2.) polygamy, or 3.) monogamy. In other words, we have Tiger Woods, fundamentalist offshoots from Mormonism (small disclaimer: lumping in Mormons with the fundamentalist polygamists is not cool), or Mr. Wright himself. He seems literally unable to contemplate a triad, a married couple agreeing to be sexually non-monogamous, or any of the panpoly of frameworks that characterize the sex-positive polyamorous community.
This is problematic because it colors almost every discussion of polyamory in our society. It's pretty clear when you talk to most people about it that they've got patriarchal polygamy in the back of their minds, and filter everything you say through that lens. To put it mildly, this isn't a constructive framework in which to view the subject. Comparing sex-positive polyamory to ancient polygamy is like comparing modern homosexuality to Athenian pederasty. Yeah, both involve same-sex attraction, but the cultural and ideological conditions are so radically different that concerns that apply to one are unlikely to apply to another. Only homophobes are concerned that homosexuality in our society will largely consist of older men having sex with younger boys of questionable ability to consent. Likewise, though the effects of sexism and patriarchy on current models of polyamory are of concern, only woefully misinformed people ought to worry that modern polyamory will even remotely resemble the chattel slavery that characterizes polygamy.