While it's certainly compelling, I fear that it's far too obvious a point for those whose wishes point the other direction. It seems that our capacity for willful blindness increases in direct proportion to the obviousness of the point in question.
Why else would we see this never-ending (and yet-to-be-successful) search for the "gay gene," which would "prove" that homosexuality is "normal," sort of like having blue eyes, when the physiology is there for all to see?
I was also surprised to see that the author did not bring in the old question of "why do bad things happen to good people?" From his perspective, homosexuality would certainly fall into that class of conditions.
Finally, while it may not have fit too well with the rest of his point, he could have added in the observable fact that the "gay rights" movement moves in lockstep with that group of activists who want more help dealing with the medical consequences of homosexual activity -- which come as a direct consequence of violating the physiological imperatives the author so rightly points out.