Not to tramp on any toes. But in a lot of cases the woman sleeps with the man and when she breaks up with them. she keeps his child away from them. I know it's illegal in a lot of states these days but hey... why make children by men and terminate their rights.
The woman is usually doing it to protect her child and often - herself.
Lots of men insist on an abortion and aren't committed to a pregnant female but once the baby is born (and a little older) they suddenly want to be involved.
You need to understand the mother's suffering and why she might have held resentment towards the father. If she never had a proper father herself she might be even more protective and not want a fickle man around that might let her child down.
No, my daughter's dad chose to walk away. He's back now, but he missed out of two years of her life because of his own doing. No one kept him away, it happens. Things like this are not as cut and dried as people think