Are parents' incentives really that strong? We need all sorts of laws to prevent parents from exploiting or maltreating their children. It seems that parental instincts are not very reliable.
Having kids doesn't make you wiser.
But it makes you more receptive to arguments about anything that could endanger their safety and future.
My wife has started to be much more environmentally conscious (vs. economically conscious) over the past year, and I think it all started due to one off-hand remark: I said that I hope our (then about-to-be-born) daughter will be able to experience snow. She brought up that particular phrase to me many times now; it seems it really stuck in her imagination.