I absolutely agree that sexual reproduction did not come forth from any pathology — I think it stems from a more spiritual concept, i.e. the magic of the attraction between the masculine and feminine polarities — but I'm not so sure about the supremacy of sexual reproduction as a mechanism when it comes to diversity and adaptation, Sister.
Viruses are the most adaptive of all organisms, and yet they reproduce asexually. Granted, they can only reproduce by infecting a host and adapting their own RNA — most viruses have RNA, not DNA — to the DNA of the host, but it is asexual reproduction. The concept even formed the basis of the way the alien xenomorphs reproduced in the "Alien" movies.
For those not familiar with the franchise — what planet are you from? — the xenomorphs' reproduction cycle starts with a queen, who lays eggs. These eggs are however more of a kind of cocoons, inside of which sits what in the franchise's production terms is called "the face-hugger" — a spider-like creature with very long legs and a long, muscular tail.
When the face-hugger senses the proximity of a large enough life form, it will open the cocoon and leap out onto the other life form, wrapping its tail around the victim's throat and forcing an appendix down their throat in order to lay an egg inside the victim's body. Shortly after that, the face-hugger dies and can be removed from the victim. After a few hours, a baby xenomorph "hatches" from the victim's chest — thereby killing its host — while bearing visual similarities with the species of the host. This baby xenomorph will then grow into a full-size adult in only a few hours.
Most of the xenomorphs seen on screen in the Alien movie franchise have "hatched" from humans and are bipedal. However, in "Alien 3", a xenomorph can be seen which "hatched" from a dog, and it is quadrupedal. Likewise, in the two "Alien vs. Predator" crossover films between the Alien franchise and the Predator franchise, one of the Predators is infected by a face-hugger, and after he dies of the injuries sustained in combat with the xenomorph queen, a new kind of xenomorph with mandibles bursts out of his chest, and this specimen also grows into a much larger and more muscular adult than the other xenomorphs, becoming their new queen, and laying its eggs directly into a human host body without going through the phase of laying pod-eggs with face-huggers first.
The xenomorphs seen in the prequel movies of the Alien franchise — i.e. "Prometheus" and "Alien: Covenant" — are also different, and these movies shed more light on the origin of the creatures, i.e. they were created by a technically advanced species of large humanoids as a biological weapon.
The concept is interesting because it upscales the reproduction of viruses to the macroscopic level, and it is not unthinkable that somewhere out in the big universe, a species like that would actually exist, even if only because it may have been genetically engineered that way. It is certainly food for thought.