I can tell you from personal experience. When you have a baby or toddler who is curious about wires and quick about it, those safety features are very handy!
Even as an adult, I like Apple chargers because I know they were engineered well enough to not shock me. I have no problem leaving the connector on the couch, accidentally sticking my finger on the contact points, etc.
It is a nice peace of mind when my brain is not on edge that it might be plugged in when I see it laying around. I could not say the same thing for my cheaper USB phone charger.
