I once worked with a guy who had 4 children in 5 years. He took a lot of parental leave, sick days and often slacked off early. As soon as the last baby was stable he quit for a new job. Companies and teams that are too generous get shafted.
There will always be people like that, but if the societal good outweighs the few bad apples, I'd argue that's a plus in general.
Maybe I am too cynical, and having >= 5 kids is the outlier.