Whew, okay... I'm going to try and take this really slowly because you seem to be struggling here.
If someone says "I only make YouTube videos for the fun of it," then I ask why they don't just set everything to private? If it's true that the motivation to make videos is to have fun making videos, why are they posted publicly? Why did they give it tags and search terms and advertise on here? Someone who is making videos just for fun wouldn't care about publicity and wouldn't put the work into SEO. They would have fun making their videos and that would be all.
The POINT is that we ALL are doing this for the "public" aspect of it. That's why we're on YTTalk. We're looking for ways to grow our channels, to get views, likes, comments, and subscribers. When I say "you might as well set your channel private," I'm not TELLING them to set it to private, I'm getting them to take a moment and realize why they WON'T do that. Because, not to repeat myself, no one on here has no care about publicity and traffic.
Okay? You following me now?