Now that I've tried to understand LINE Webtoon a bit more, I think I get (partly at least) why it's so much peaceful here.
On webtoon, notwithstanding the sheer number of readers compared to Tap, they don't have a forum where people can learn to know each other and unless I'm mistaken, they don't have profiles at all. Which means that when someone posts a comment, his name is just that : a name. The others can't click on it to see if the guy is a regular troll or has his own comic or anything... It's almost anonymous... And who says anonymous says it's troll's open bar...
And has @yvettegustafsson said, the fact that the staff here is so present and friendly and approchable sets the tone to the whole site 