science

It's not the absolute truth. But it's most likely the largest part of the explanation.

People like putting blame on "society", and while societal pressures surely play a part, the reason it's so nice to mainly blame society is because it creates a problem that has an acceptable solution.

Because what do you say when you say society is mainly to blame here? You're saying it's completely fine for many men not to have sex. Just have to fix society making it hard for them to live without sex. If my assumption is correct though, that doesn't help those men very much. But who does it help? Anyone those men would want to have sex with, because they're not under "threat" anymore.