I loved the film Tough Guise. Even though it didn't analyse the reasons deeply, it manifested the changes in masculinity throughout the years, and how people are manipulated to act on more extreme perceptions of the characteristics of gender stereotypes. It also showed very important and inscrutable consequences of the phenomenon.
Indeed, it is a sore sight that people are once more reducing themselves to animals, as physical attributes are becoming more and more important in social success.