What is problematic with viewing history as simply "the study of great men?

"The great men" who, according to this view,  are behind the events in the history never actually work alone: they are the product of their times and are supported by many people. For example, people could see Napoleon as having a great influence on the history, but without his followers, Napoleon would not have the impact he had. So the problems with only considering the great men is that 1) we omit many other relevant people 2) we have only a shallow understanding of the past 3) we don't understand how the social opinions shaped the deeds of those great people