I dont know if I entirely agree with this.
Sex is a very messy, dangerous, random, and not even efficient means of reproduction. In fact, if it didn't evoke such powerfull emotional and physically pleasureable reasponses I doubt humanity would be here today.
I believe there are many many indications around us that show that we are on the cusp of a major evolutionary step in humanity. Genetic engineering, AI, Robotics, nanotechnology all have tremendous implications for our future. While 10 years ago, it was fantastical to say "Soon people will be able to download their consciousness into a computer/robot and live forever (or a much longer time than 82 years)", I believe most futurists would agree that this is now a question of when, and not if. Possibly even in our lifetime or our children's children's lifetime. Once this is done, and a few individuals begin to do this it's guaranteed that they will now be superior in many way to the pure wetware which we have evolved from. Once this step occurs, how long will it be before wetware (or at best, just homosapiens) are just a memory? History has shown us time and again that once an evolutionary step of this kind occurs, the previous species is wiped out within a few generations (relatively speaking). Further, given the nature of sex as both a reproductive and emotional act, would it survive a transformation like this? Maybe, maybe not.
Just something to consider considering this all may begin to occur within the next 100 years. When you place that in perspective of 700,000 years of civilization, it's very very soon.