Child support is an extremely messed up system as is. So many people have been required to pay child support for children they never wanted. This is a huge problem that needs to be fixed.
The child support system is messed up in that as it currently works it tends to exacerbate poverty at least as much as it alleviates it, without doing anything to actually encourage parents to stay in their children's lives. But the basic principle that a parent should support their child is pretty much the foundation of the entire social fabric. Whether they "wanted" the child shouldn't matter.