As they mature, they will know, better than we do, that op. cit. If they grow up disliking or distrusting people who look different, it'll be because some adult told them to. But the internet is the great equalizer. Anything you write or draw or paint or compose, to show the world, is offered up without a hint of what demographic groups you fall into. That's toxic to intolerance.
Hate requires that the target of hate be different, be inhuman.
If we can't convince ourselves that someone is so very different from us that they deserve to be despised, we can't despise them. We just can't. It's also toxic to the message of Holocaust-denial. That belief system requires faith in the notion of a massive Jewish conspiracy which has controlled the world for this century at least. This conspiracy must have managed to forge thousands of documents, just for starters.