Comments are feedback. If they build a bad place, they should get bad feedback. However, I agree words such as, "Idiot, moron, ect." should be deleted. I think noob and fail shouldn't be, however.
It would hurt an 8 year old more emotionally to be called a kid by a highschooler then it would to be to have their place called fail. Even if they are hurt, they definately won't be scarred for life.
@Ozz
But it would emotionally hurt an 8 year old kid to have their place called a stupid fail created by an idiot MULTIPLE times than it would for a high schooler to call them a kid.