It just makes no sense to say the contract is legally binding even if the kid is the result of cheating.
And some children would spend the money on games, etc, not food, so it's probably best that it doesn't go directly to the children.
it's administered thru the custodial parents
it is a terribly flawed system, not unlike sending welfare checks to layabout parents of kids in a single-parent household and hoping the kids receive enough of it to maintain their welfare
but unfortunately, it is better than any other system yet devised