All this article points to is that the pair bonding, which we call "marriage," is a social construction. We want to impose all kinds of expectations on marriage including long-term sex and passion. Equality, where it exists, is brilliant and the best thing ever to happen to pair-bonding. To equate sexual frequency as a value on the same level of importance as equality is fun for a sociologist, but silly in reality.
Sex is weird and idiosyncratic. Individuals first have to figure out what their own sexuality means and then how to negotiate sex with another human. Then how to figure out marriage.
Equality, however a couple wants to define it, is non-negotiable in my world. Sex, though, always negotiable. However - it took me a few relationships to figure that out. The non-equal relationships soon become non-sexual relationships as well, because the anger is so great. The more equal relationships -- not without their issues for sure -- continue. I'd love to hear from b_b on this -- but the article is not worth reading -- especially at 5000 words.