Why? Being an 'American' automatically makes their critique irrelevant?

It makes it imperialist intrigue. His critiques are made of ignorance and he knows nothing about the history, context and conditions of the nation he criticizes. A revolutionary is to avoid imperialist intrigue and attacking the enemy of their current state, as that is chauvinism. He exists as part of the grand western tradition of social chauvinism and does not attempt to break from it.