it takes few years to replace a baby that died but it takes few times more time and even more times the money to replace an adult that died. you can think of children like blank pieces of paper that are not nearly as valuable as painting that has a lot of investment put into. If you look at it from purely logical perspective, children are quite renewable resource because of how little investment was put in them compared to adult human that was educated and some company put a lot of money into him if he's a worker.