My experience is that there is local control of the window tinting on JAL. But they seem to central set them to max darkness, like they would go around and ask people to close their blinds. But the can be set to clear again by the passengers.
Normally they will also ask people who later keep them open extensively to close them again. I have never experienced the same as you.

That being said if someone is in a window seat and want to look out of the window, why should that be forbidden? But this is one of the hot topics of airline travel. Like seat reclining.