There might be a difference between those two signs, but I'm not sure it's as profound as you make it. People change and learn as they grow. Someone holding a "Need $$ for beer" sign today may be holding a "Will work for food" sign tommorow, and who knows, perhaps "Now hiring" the next. Should we make sure the man starves to death in the first or second phase before he has a chance to mature and contribute to society? What percentage of humans are irredeemably intolerable? Can we not afford to help them out anyway just to make sure we don't miss the others?
I agree that people ought not have babies they cannot afford, but given that the entry bar is low and, ya'know, it does happen, is it fair for society to leave the child adrift in the wind to... punish its parents? Does society work better when it's comprised of adults who were such children?