There's nothing self-evident about that at all. All species of animals have a homosexual population; this has been observed in the wild as well as with domestic species (dogs, etc.). To be sure, it is a minority behavior, but "contrary to nature" is stretching it.
Then I suppose you consider medical advancements to be unnatural and thus bad too as compared to the natural course of letting the diseases just kill you and similarly modern form of communications bad as well over the traditional flapping of mouth flesh.
A casual examination of nature would demonstrate your statement to be false. Your statements are both extreme and unfounded, which is a curious state to start from when you have very little objective information about a topic.