The point I think the parent is trying to make is that some times debating certain ideas is validating them a little bit. It's as if someone asked me to jump off a bridge: discussing whether he should jump or not would be like saying "there is some possibility that you convince me and I jump off the bridge".

Indeed, you should enter a debate with the idea that the other might convince you, right? If you are not going to change it it's not a debate.