I find this very interesting, as it is more or less directly opposed to the traditional (sic) framing of marriage as for better and for worse; and it explicitly

I find this very interesting, as it is more or less directly opposed to the traditional (sic) framing of marriage as for better and for worse; and it explicitly foreground self interest where traditional marriage is/was often a contract at least as much about family, business, or social interests, as personal benefit. Restated, this view asserts that marriage, or, the partner, are of value only in as much as they remain beneficial on a limited horizon extended by limited extrapolation to future goods. That sounds to me like precisely the same sort of short-term-results focus that is increasingly being criticized for producing non-desirable behaviors by public corporations beholden to hit their numbers, regardless of long term costs, externalities, etc. etc. I am NOT being critical, btw. This is a total valid and rational formulation, and it has refreshing clarity. That said at a personal, anecdotal, level, I can report after 15 years of marriage (and 25 together) with a partner, that there seem to be good reasons for the traditional formulations to have evolved as they have. E.g. that there is great value when the market is down (e.g. under the decade-long stress of parenting young children) is knowing that your partner has committed (is stuck) to you, even when you don't have the resources to give them your best self. We all err; disaster strikes; forgiveness takes time; sometimes it will take more than a day to heal. But YMMV :)