It's much harder to estimate the demand of a child care center than that of a gym or a cafeteria. Not every employee will become a parent and those who do so will only have one or two children in the lifetime.
On top of that, some would prefer an outside child care service, specially if the position has a lot of traveling involved (can your partner or caregiver bring the kid to campus when you are not there?) Even if you decide to do it. ¿How many people should you hire? ¿What happens when the employee is fired or quits? (it's hard to find a daycare center in short time), add insurance, etc...
The way most companies solve this is by subsidizing the daycare facility of you're choosing or allowing for remote work some days of the week. It's more efficient.
That being said, not sure what the policy at Apple is right now.