Clearly, the"great man" theory of history will always be ripe for debate, but as shown by a choice reading of CEOs the presence of a strong, charismatic leader can hold more sway in business than elsewhere.
However, I also believe that every great leader has a huge bias toward the inside- out, GreatMantheory of history and human nature regardless of whether this theory is objectively valid or not.
Both have advantages and disadvantages, much as the broad, impersonal-forces approach to the past and the heroic, great-man theory of history each have theirs.