Probably a lot of parents would find solace in year round school.
But thinking back to my experience, (that's all I've got to go by) I'd be poorer for not having those summers off. No camps, no organized activities except maybe a week(2 hrs a day) of swimming classes a couple times, I was on my own to amuse myself. Of course I started working summers when I was eleven or twelve, so that took care of big chunks.