It would seem that actors deciding to take parts because they like the people making the movies might be more common than we imagined it to be. Sally Field isn't a fan of superhero movies, and so she had no great desire to play Aunt May in 'The Amazing Spider-Man,' but she agreed to do it as a favor for a friend. If it weren't for the presence of Laura Ziskin as the producer, she'd never have done it.
Field confessed her motivations to Howard Stern - who seems to have a knack for getting the truth out of celebrities - during an interview on his radio show. She didn't have a specific objection to the character of Aunt May; she just didn't feel that 'Super Man' was 'her type of film.' Ziskin was severely ill when she was producing the movie, and Field knew that it was likely to be her last film. When the call came, she couldn't say no.