You are thinking in cliches. "Shielding our children from all the bad things that happen" is indeed the duty of any decent parent; reverse the statement and you will realize that you are advocating child abuse as educational. The issue is not whether you want to lie to your children, but whether you want to lie to them. That is, a particularly brutal piece of political propaganda, meant to inculcate racial guilt among adults, has been painted directly above a children's school playground. If this is exposing children to real life, a paedophile is an educator.