I think a lot of critics favor this film because, unlike so many others, it contains only archival footage. In other words, dialogue with people interviewed occurs during the viweing of the races and the racer. Viewers who knew practically nothing about Formula 1 racing (including myself) come out surprised at how interesting it can be. As a result, this film is over-rated because it may have paved the way for further comparable documentaries.
The politics, cheating, and disfunctional teamwork behind racing, as well as the racer's personal life are only touched upon. The director and screenwriter introduce the racer's devotion to God and Racing, but little else that shaped his character and career. So by the end, some viewers feel like the documentary ends too soon.