Ask HN: Why not one click anon posting handles?

In a typical case someone wants to reply to a comment but doesn't want to use their real handle for some reason. So they end up using a throwaway account which takes a effort and wastes time. Why not enable this functionality for people with certain karma so they can make an anon comment w/o signing up for a new account? Upside would be comments without fear of downvoting which can prevent people from being fully honest. Enabling this only on accounts with a certain karma level should prevent at least some abuse.