One has to wonder whether Preyer-Johnson would apply the same standard if parents demanded the right to decide what age was appropriate for their children to learn that short people exist, or differently abled people, or exceptionally talented people, or... (I think I've made my point).

This presents an interesting challenge because it's unlikely that any parent who would object to their children being exposed to such factual information would ever come to think it's appropriate to acknowledge the existence of gay people. They'd probably prefer that we just shut up and remain invisible. As a result, more children grow up in ignorance and fear.