You guys are being too hard on child swap. Requiring everyone that rides to have a FP will isolate the little child that can't ride. My 4YO will be too short for the 44" rides on our next trip. If the other four of us all need to have a FP to ride Everest, then the 4YO will essentially have one of their three FP that they can't use... they can't ride anything by themselves, and they can't ride the ride that the entire rest of the group wants to see. If two of us FP Everest, and the other three in the group FP the Safari and the two taller ones eventually use a rider switch pass on Everest... I think that's exactly what Disney wants. It's much nicer for families to not have to make that choice. If somebody uses their 1YO to double up their FP on all height requirement rides, then they're just being a jerk to their kid. The principle is the same even if the kid is too young to have a ticket. If people only use the "extra" FP to ride height requirement rides, they are stealing the short lines benefits of FP from the little one.
Is Disney required to offer it? No. But I think it makes sense to give those young families a bit of a leg up. They're probably in the park for less time and are slowed down by the baby. If Disney can give those families a bit of a better experience, they're probably more likely to return when the kid is 8 and they don't need rider switch.