In HN's defense, the original email contains relevant information, and it should get attention. Of course, it has to be understand in context, as things change (specially after such thoughtful email) and not every app has the same constraints as the Yammer.
Not all of HN's discussion is keen on it, but often some of it has good signal.
He's not wrong, but at the same time I don't think anybody who so enjoys pissing contests on Twitter can afford to be too condescending about slapfights on HN. The last thing either place needs is more hipper-than-thou posturing.