School districts want kids for the same reason start-ups want customers: it's hard to scale with smaller demand. Yesterday when I was in SF, I saw a sign hanging on the fence of a schoolyard: "SUPPORT YOUR SCHOOL - BUY SCHOOL LUNCHES!" Apparently, so few students were buying school lunches (and instead bringing their own) that it was becoming more expensive to provide it for the ones that do buy it.
Children who grow up in a city go on to invest in that city. Children also require services that drive the local economy, from babysitting to clothing/toys/food.
I know you don't like sitting next to a table full of kids at a restaurant. Me neither. But children are necessary components of a thriving community.