Interesting, and I think much to agree with.
But look at how you phrase this -- and then look to the immediately preceding post by
@John D. Brey, who took an entirely different (as I said, 90 degrees) tack. As you'll see in my upcoming response to him, I see him (mis)using "nature" to argue for why everybody should be the same. Yet, I can point to another eusocial species (ants) and make the case that since only one female and one male mate, and create a whole community of non-mating others, or that many species mate and have orgasms (he focuses on that a lot) only for the single purpose of pro-creation while others (bonobos, for one) have lots and lots of lovely sex, of all sorts, for purposes having nothing whatever to do with procreation -- but perhaps more for preservation of the community that will ensure the progency created by the very few orgasms that created them, will survive.
It's complicated -- and again, I think a liberal can deal with that complexity, and I think it confounds the conservative who wants to feel the safety of homogeneity in their surroundings.