It is better to maintain health, than to treat disease. Simple. Logical.
It would make sense to keep your car working at the best level it can, through regular maintenance, than to wait for a problem to show up before you start taking care of it. Short term vs long term thinking.
Kids fall between 500 and 700 times on the rears before the age of 5. That is a LOT of physical stress and trauma. Combine that with childbirth, as the singular, most traumatic event in our lives (even vaginal birth produces incredible stress on the necks of babies, which means doctor assisted births are exponentially worse), and we have the recipe for neurological disconnect producing developmental issues early in life.
Children need to have their spines checked for spinal misalignments (subluxations) as soon as they are born. By keeping the spine in good alignment from birth, we make sure that the brain to body nerve flow connection is strong. This spinal maintenance has a hugely beneficial effect in helping children express normal functional development.
In other words, we check, and when necessary, correct the subluxation, in order to ensure that the child is able to adapt to its environment and express as much potential as is possible. Well adjusted kids are healthy kids.