Here is an "intellectual debate" for you: hairdressers are a danger to society and should be exterminated. Why don't you want to have it? Why censoring a potentially valid viewpoint?
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.
I will gladly debate this with you. Don't assume I don't want to engage, or that I would attempt to censor your view.