I agree for the most part with Tim. An essay that focuses more on the failings of others is often the kiss of death for an application.
AdCom is looking to get more insight into how you interact and deal with other people - especially in challenging situations, environments, etc. The Wharton MBA program has many activities and classroom exercises that involve personal interactions, and AdCom would like better to understand your style, personality, insights, etc.
The question is intentionally broad and open to reasonable interpretation, but don't forget the core purpose(s) of the question when composing your answers.
-Victor
WG '11