> I learned the hard way long ago: more often than not, people don’t actually want (or need) trees, they just need the appearance of them.

I've been noticing that this is one way in which HN and Reddit differ. On HN, a child comment is a nextSibling of the parent comment, with indent set to parent's indent plus one to simulate the appearance of trees. On Reddit (or at least old.reddit.com, don't know about the new site), a child comment is actually nested inside the parent comment.