I somewhat agree with you. I think stuttering is both physical and psychological, and it varies on an individual basis. For example, for some people, the physical part is much more harder to override psychologically, while for others it's easy. In any case, I think all stutterers should work hard on the psychological/emotional aspect. I noticed I'm much more fluent when my sympathetic nervous system is inactive. Your heart rate shouldn't accelerate right when you're about to speak and you shouldn't be tensed up. If you are, it means you still need to work on the psychological/emotional part.