A well-beaten child might obey best, but obedience isn't the only goal of discipline - nor agreement the only goal of argumentation.
I've heard this referenced somewhere as the difference between persuading someone and convincing them. You can apply rhetoric or logic until someone verbally accepts your arguments, but that is not the same as getting them to genuinely believe that what you are saying is true.
Sometimes people will say "Okay, you're right" just to get you to shut up.
Scott, known on LessWrong as Yvain, recently wrote a post complaining about an inaccurate rape statistic.
Arthur Chu, who is notable for winning money on Jeopardy recently, argued against Scott's stance that we should be honest in arguments in a comment thread on Jeff Kaufman's Facebook profile, which can be read here.
Scott just responded here, with a number of points relevant to the topic of rationalist communities.
I am interested in what LW thinks of this.
Obviously, at some point being polite in our arguments is silly. I'd be interested in people's opinions of how dire the real world consequences have to be before it's worthwhile debating dishonestly.