I haven't said that anyone who needs money for their kids is a bad parent at all. If you claim the benefits you are entitled to and do not feed and clothe your child, that makes you a bad parent.
On the top of bad luck, if you have a child that is unplanned or you lose your job straight after having them then you will still get benefits that will feed and clothe your child even if you have to take a large hit in living standard.
My basic point is that whatever your circumstance, the state will protect and give you enough to live and eat on. If you spend that money badly then that is on you and I don't believe that giving such parents a bit more money would make a blind bit of difference.