In all seriousness, I think it's related to how so many people prefer texting on their phones—social anxiety. And there's a general lack of energy, lack of interest, and apathy pervading society. Japan has it worse than Western countries, but we're not far behind.
Also, the male “interest in sex” hasn't diminished, but he satisfies it by himself without bothering to pursue women.
And this crap doesn't help—