I guarantee that a lot of favorites are just ‘to read later’. In that model, articles themselves are read at once or go into Pocket-like services, with selective perusal of comment sections. In most cases, comments are sorta predictable, or interesting perspectives are quickly exhausted—and only especially rich threads go into the favorites to later be pored over. However, interesting ‘Ask HNs’ are obviously followed by lots of interesting comments (hopefully), so they fall straight into the category to be sorted out with attention.