"I dislike bratty teenagers as it is and don't care: in what field exactly is a preteen an expert, and why should they be allowed to troll me as Zach Silverstein did? There are millions of websites for brats; let him and his cohort play, fling doodoo and cast snark at the other 9,999,999+"

Sounds like a clear violation of the "be nice" rule to me. I don't know enough about Quora to know what kind of tone is normal there, but I would be perfectly happy with a community that banned anyone who spoke like that.