I really enjoy how people try to dispel their outright attempts at bullying behavior with an emoticon. :)
Meanwhile, the HN homepage is not some carefully guarded display of exceptional merit, and no serious "hacker" would take the things posted here to be above reproach.
I think it was an attempt to add a cheeky or comical tone to the response, instead of outright saying "Yes, you're missing something" or the more curt "Yes". But if I helps,