Motive arguments and Mutual Assured Destruction

My claim is that everyone's belief choices are partly the result of reflection, and partly the result of motives, of which none of us are fully aware. No one side in the discussion has a monopoly on rational or nonrational motives. So motive arguments are a wash, and if they are introduced in place of actual arguments, the result is mutual assured destruction, since each side can "bomb" the other with an equal measure of motive arguments, and blow up the discussion permanently.