I'm not sure if it's attributable to porn though. I think it's rather our individualistic, bordering on narcissistic, culture that is driving this.
As the old saying goes, it takes a village to raise a child. The next best thing after the village is the family.
But in a society where the individual is celebrated and divorce is so common, the whole burden of raising the child rests either on the mother or the father. And that is just too much to deal with.
I think if you look back in human history it was natural that the tribe would take care of all the children, thereby spreading the burden a lot. But we don't have the tribe anymore. And the families are now breaking apart, too.
