Arnold Schwarzenegger stated on the "Pumping Iron, 25th Anniversary Edition" DVD that the investors asked for a little more drama in the film, because simply having the footage the bodybuilders training and eating was rather boring.
On its face, bodybuilding is a rather boring "sport", to the average Joe. So, George Butler, Arnold Schwarzenegger, and others had to spice up the film. Hence, you have all the "psyching out" and "mind games", being employed.
Arnold even stated that he got that bit about not attending his father's funeral, as it was during contest prep, from a French bodybuilder. The Oak stated that his father passed away three months AFTER a contest and that he saw his father, shortly before he died.