I get all that... I still feel that the schools either don't know how disruptive this is to parents, or they just don't care.
...
But my guess is that the teachers' union would rather reduce actual school teaching hours than they'd support additional burdens on teachers outside of normal instruction hours. And my guess is that the school districts are more beholden to keeping the union happy and costs as minimal as possible [good point about the power/water/AC etc] than they are to keeping parents happy--the parents don't have much choice in the matter.
I'm trying to wrestle with the tone here. Because the way it's phrased, I don't totally see a way out.
Before I go further, when you say normal instruction hours, do you mean in the course of just a week?
Edit: I'm more awake and can phrase it better.
You've pointed out, you want them to provide more consistent childcare. Which is a good goal. But working outside normal instruction hours is going to have costs. It's already a job that often has a decent amount of unpaid spillover time. So that extra time is gonna end up being time and a half. Also, there's a basic question of what it means to make something officially more than a 40-hour-per week job (as compared to unofficially now). Your time is valuable, but so it their's.
The most logical solution would probably be to push PD into the summer hours, but that increases the costs of personnel 2.5-5 percent, which isn't small, plus incidentals, depending on how much time these hours take. There could also be the plan of paying for some kind of staffing to organize something in those extra hours, but that likewise costs resources.