Somewhere in Surely You're Joking, Feynman writes about attending a meeting of the Great Men of American physics where strategies for some crucial ingredient of the nuclear bomb program were debated (separation of U235?)> Compton may have been the chairman. One by one, each advocate gave a description of a proposed method. Feynman, still a grad student, was soon beside himself with frustration. Couldn't they recognize that the best idea had already been presented?
Finally the presentations finished, Compton looked up and said: "We can all see that idea X is the best," and all concurred.
These were indeed great men, concluded Feynman.
It might be nice if more arguments went like that, but they don't. Mostly we get distracted by ideology or ego and fail to recognize the best arguments. We may not be bright enough to recognize the best chain of logic. Or, we may just differ so much in fundamental world view that our assumptions lead inevitably to different conclusions.
I still find arguing with intelligent people very useful. At the very least they should challenge and expose the weaknesses in one's own logic. That may not change my conclusion, but it at least helps me understand the issues better. Lee, for example, is particularly good at finding places where my facts or logic are shaky. I remember that I happen to owe him some facts, for example, so I guess he is winning our latest dispute ... at the moment.