You have some interesting ideas there. It's worth expanding on. Though, some of the people below have made good arguments. But I think you're on the right track.
Partnership for the sake of love is a comfort of a society where even the common people are rich enough to not be dependent on political manouvers to make it in the world with a reasonable degree of certainty(unlike serfdom for example, where you are something akin to a slave for a local lord). It isn't exactly common among humans, if we look at our history. Love is more alive now than ever, simply because we are more free to live it(also for social reasons, see the "man is the head of the marriage" and "a woman's place is in the house" attitudes of much of the last century alone).
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