> Moral and legal obligations that restrict your choices don’t make you “property”.
You know, we could debate the appropriateness of the word "property" in the description all day (and I'll get back to that later in this post), but it is, in any case, tangential to the point which is that the utility of exclusive legal monogamy as opposed to tolerance of polygamy in assuring men with partners is demonstrably, empirically only present when comparing systems in which women have a legally inferior, subordinate position, and that whatever social utility can be said to derive from that effect is not achieved by choosing exclusive legal monogamy in systems with more gender-equal ranges of social and economic freedoms and choices.
> By using the word “property”, you’re invoking the mental image of some of the rights associated with physical property
Yes, deliberately so.
> like the near absolute right to destroy and use for your own purposes.
Yes, and in the systems in which monogamy has the effect of providing near-universal guarantee that men get stable partners, that is a very close approximation of the case. Women are disposed of to men by the men in the family they are born or raised in, often in explicit or implicit exchange for other property, and once so transferred the receiving man has relatively impunity to use them at will, including often the right to impose corporal punishment and the right to free sexual use at his whim without regard to her preferences; they universally include widespread legal discrimination against women in economic activity, and often include outright legal bars on women engaging in wide fields of endeavor, and often restrictions on women even owning property.
> Marriage is not such a thing at all.
I didn't ever say marriage, in general, was a relationship in which women were property, I said that the social contexts in which monogamy as the sole legal form of marriage actually produced the outcome that virtually every man was able to have and keep a partner are ones in which women (not just in marriage) are treated more as valuable property than as coequal members of society.