I don't understand at all how anyone can consider this as rude or abusive.
It's not particulary helpful, that is true, but it's not rude and it's not abusive. You might have flagged this as "not an answer", but even that is not really true because the answer is factually correct - a disconnected system can't be attacked via the network.
Become a valuable member of the community by asking good questions and/or giving good answers, get reputation and you will have the chance to vote, including the option to vote to delete an answer.
(BTW: I didn't handle that flag, but I would also have denied it).