Yeah, couldn't agree more. They also can be annoying online, so people just ignore. On Reddit you often see very long, deep, threads with 1-karma posts that nobody even bothers to vote for. On HN those long debates not only take a lot of space, and you often see moderators telling people to stop.

Sometimes you gotta preemptively "lose" a debate, by not answering at all. At most a "Alright, I get your point but I disagree" which also doesn't really add much to the discussion.