Nobody ever mentions Darwin and the largest part of "On the Origin of Species", which is about adaptation. (That overly mentioned "survival of the fittest" is actually just a small part of the book).

"Name a modern blight, and someone, somewhere, is ready to blame it for messing with the modern libido."

Fair enough; it's probably a little of all of those. Also, the moral imperative to have children has vanished, the result of overpopulation. And if there is one constant throughout humanity's sexual history, it's that our morals and our actions tend to support what we need to move forward, even as we are not conscious that's what we are doing (we see the trees, but in the way we need to keep the forest strong).

err...because modern society and everything in it (#metoo, Facebook, gender indifference etc) is all geared towards self-righteousness and will ultimately cause the collapse of normal human interaction?