Sex is the drive for everything we do. Learning skills, gathering resources, becoming educated, everything is for a little hammer time.
Turn it off and there's no point in doing anything at all.
That's not to say you consciously pursue everything for sex, it's the DRIVER. Why do you have a car? because you have to work, why do you work? because you need to eat. The need to eat is the driver for having a car, but you're not constantly thinking about pop-tarts every time you're in your car. Well maybe you are, pop tarts are delicious.
Sure, older folks already have the kids (or biologically think they do) and are driven more to support that posterity than to produce it. But they're still driven by the desire to have posterity.
Everyone who says they'd turn it off, or have turned it off...I would not want to be you. If your life was a TV advertisement there'd be a subtitle reading "experience not typical." I absolutely would have more money and more time to devote to lonely pursuits without sex.
But fuck that shit.