I though the same when I first saw Jiro (and was amazed by the passion), but I couldn't shake the feeling that I had just watched an 80 min advertisement for his family. Most of the reputation, and thus success, of a restaurant, in a place as competitive as Japan, is based on the heredity and life-long devotion of the chef. Some top restaurants boast third-generation sushi chefs (a chef whose father, and grandfather, devoted their lives to the art of making sushi).
You can view the movie as both a statement about the passion for perfection, and as a way to advertise Jiro's family, so that the restaurant, when Jiro retires, may retain its prestige and success. And, I think it is an amazing feat, by the film maker, that they were able to produce a film that made a statement about passion, featuring a specific person, without it feeling like an advertisement or deification.