For one thing, most companies have hard time keeping employees working for them so this 'we have hired too many good workers and now we have to get rid of them'

For one thing, most companies have hard time keeping employees working for them so this 'we have hired too many good workers and now we have to get rid of them' does not happen nearly as often. As others have pointed out, it's not a 5 year leave. Assuming it one to two years and assuming you simply cannot afford to have more people on payroll it's completely OK to hire somebody specifically for a year or two. Not all work contracts are indefinite. I have no kids, don't plan on having any but it's kind of crazy how 'hail corporate' some cultures are. We're humans after all. Let people spend some time with their newborns instead of forcing them to make more money for somebody 3 weeks after giving birth.