Biology is a convenient and often appropriate scapegoat for sexual behaviors and decisions, but only because I think we are wary to delve into what may very well be manipulative or deceptive behaviors, not because they come from a place of malevolent intent, but that the presumptive consequence is a selectivity they dont want to be subject to.
I disagree that biology is scapegoating. The sexual dimorphism of our species is the very foundation of this couple's (K&D's) frustration. As a man his hormonal drive is ON all the time. As a woman hers isn't AND her brain is wired for context not just physical attraction. He must also behave romantically to light her fire, finding new and inventive ways to woo her even though she has/is already committed to him. She? All she has to do is take off her clothes to light his.
What's manipulative is the religious & moral indoctrination we all suffer from childhood which says we MUST have and maintain lifetime monogamous relationships when our species is not instinctually that way. Even those who are not raised in a religious faith are steeped in a culture which is. Almost no one escapes the expectation of this cultural indoctrination.
As I've said here many times before indoctrination is a ten dollar word for brainwashing. Many individuals--male and female--are middle aged before they realize this, if ever, and begin to liberate themselves.
Just from a general, tropish standpoint, we already see men starting to shy away from marriage and long term commitments to women as is,
We also see record numbers of women doing the same, liberated from traditional roles/expectations of wife & mom. You continue:
what type of relationship prospects do you think low/responsive libido individuals can look forward to in a world where high libido persons know upfront their sexual intimacy needs will most likely never be met, independent of the relationship efforts they put forth?
If low libido individuals get into relationships with high libido individuals or vice versa they can look forward to the same conflict K&D have in this video. (BTW IMO he should take care of his own needs when she's not interested in sex. He knows how to masturbate.)
Why do you think men and boys especially are indoctrinated from an early age a message of their sexual satisfaction in a relationship being in direct proportion to the relationship efforts they put forth, when women's biology says otherwise?
I don't think men/boys are especially indoctrinated. Women/girls are as well and equally. But my answer, again, is that religious morality requires it. It's trickery which ignores basic biological differences between the sexes and requires severe sexual repression of both men and women to work.
Biologically the argument can be made that long term (if not lifetime) monogamous behavior has/is being selected for in our species because the offspring of such pair bonds are more likely to survive and reproduce. What is also true is that the sexual dimorphism of our species where males are larger and stronger than females suggests that we are a tournament species where the strongest males get the most females. Indeed there is still polygamy today where one male has exclusive access to many females. It's allowed if not required in the scriptures of Abrahamic religions.
Human females are also instinctually drawn to tournament mating behavior in their attraction to high social status males. The extreme of this is seen in the groupie phenomenon. Male stars of music, film and sport bed hundreds or thousands of women who give themselves to these men. For every woman who does it there are millions who fantasize it.
Almost nothing is less attractive to women than poor men.
Are there individual exceptions and nuances to this? Sure but the population studies indicate we are 1) not instinctually monogamous forever and 2) stuck somewhere between tournament and pair bonding on the spectrum of mating behavior.