What if it's not a tradeoff we need to make? What if you can have both a dark sky and a thriving civilization?
Even more frankly, I'm not sure that availability of stargazing is a universal enough aesthetic preference, compared to extremely widespread desire for nighttime illumination, to give it any significant policy weight at all.
Maybe its value is beyond your reductionistic analysis. For example, light pollution impacts bats which pollinate flowers which only bloom at night (cactus, etc).