I respect that there is a quick fix I can do myself with iptables. However, I don't want to have to do that. I run Ubuntu with automatic security patches enabled, I trust the Ubuntu team to issue quick fixes and my server to be patched most of the time while I am asleep. I don't want to have to manually edit my server configuration to patch security holes and have to remember all these little knobs when I get EOL and have to rebuild my server.