Sure, but getting people to keep their bedrooms clean serves as an additional metric for YouTube. You can see who's putting in the time and effort to keep things clean, as well as another metric to rate the content they're uploading.
If you upload videos of kids and you're sitting back and letting paedos write this weird shit, you probably shouldn't be making, let alone uploading videos of children.
Just as if your community has an above-average number of people calling for the lynching of Muslims. Or quacks suggesting you can cure cancer with alkali diet pills. You let this stuff stick on your videos, it sticks to you and that attracts more.
Pushing this onto the uploaders forces them to think about what they're doing, and whether or not they really want to build that community.
I dunno... I see what you are getting at but it also lets Google off the hook here.
In my mind it's the Broken Window Theory [0].
It's Google's house. Google's windows. I think they need to take more responsibility for cleaning up.
It's not the creator's fault if pedo's show up and comment on their stuff at a scale they can't possibly control.
There's another side to this coin!
There is a part of me that asks "Why are parents uploading pictures and videos of their children to the internet for the public to ogle over?".
The cynical part of me says "What did they expect to happen?"
It all comes back to money though... Google have had this problem for a while but their bottom line wasn't threatened until recently... let's face it: They don't really give a shit until money's involved.
"I can tell something bad happened here" is way easier.