What are the advantages attached to eriksons eight stages of psychosocial development?

Firstly, Erikson's 8 stages tended to focus on childhood rather then the adult life through it was called a life span theory. It's also been argued that it applied to boys more then girls. Finally, the rigid structure to Erikson's theory didn't take into consideration cultural differences that may have affected the time during which an individual was in one particular stage. For example: potty training begins at different ages depending on the culture.