Earlier quoted context omitted.
I don't get why they can't just implement a way to just show content that you have subscribed to. That way you can exactly control what you let your kid look at.
That would undermine their revenue model. Youtube isn't intended to be a walled garden for children, it's intended to be a viral social platform that targets consumers with advertising (or offers to upgrade to the paid tier) through the lure of content discovery. I find it difficult to believe Google never knew these videos existed, since they appear to be an entire industry based on copyright infringement and gaming…
That makes sense of course. In my mind I thought that doing this wouldn't stop them from running advertisements. But I guess it would undermine recruitment of new content creators.