I don’t think your premise is far off, but really I think it’s simpler than that. Angry people vote, and children are an exposed nerve among “values” voters. “Won’t somebody think of the children!” has been a meme for longer than memes have been called memes. Conservativism relies on outrage and fear to motivate voters, so they manufacture it in school districts and PTO meetings. And because the outcome is so inconsequential, it doesn’t even matter if they win. They want the fight, so that progressives must spend time and resources defending against fiction. Win or lose, their supporters are energized and primed to hate anyone who is trying to corrupt their children.