Someone's prowess or bravery in battle doesn't make them more qualified to judge complex economic and political tangles and the absolute chaotic situations that result in wars.
As a matter of fact, they may be even LESS objective because the war affected them emotionally, which skews their perspective on the politics which caused the war.
In point of fact, it really doesn't matter who profited from which war, because contrary to what some conspiratorialists seem to think, corporations don't start wars.
It's easy to make simplistic, sweeping generalizations such as Butler did in his article, but though they may be satisfying emotionally, they are lacking in evidence and in objectivity. No one thing ever causes any war to start...there are always a multitude of causes, some more important than others.