This reply here sounds bitter, if you take the content posted at face value, they both made a mistake, but he's not a suitable parent because he's aiming to punish the mother through her child. I don't get your angle here, since she made a stupid decision the kid should suffer? The reality of the situation is there's a child missing a parent, at that point the blame belongs to both parties full stop.
It only sounds bitter to a person who feels women have no real agency in regards to whom is brought into this world.
Actions do have consequences, especially when you have the power to avoid the stupid ones with just a bit of effort. It is what I have taught my daughter, and what I also teach my nieces and nephews. Personal responsibility is taught within my immediate and extended family, and impregnating an unfit woman is looked down on just like birthing the child of an unfit man is.
She made her choice in birthing a child to a man who is not father material and so now she and her child suffers the consequences of her decision. In that equation, the only one I have sympathy for is the child. The child who had no choice in its circumstance. The mother receives none from me, since she chose her condition, a condition she could have easily avoided if she wanted to. The unfit father receives no sympathy from me either, when or if she decides to use the courts to place him on child support.