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.