All of the play's characters are eventually revealed as being horribly dissatisfied – particularly in their marriages and careers. Their disappointments and failures tend to make them bitter and seem to drive many of their actions. The state of the characters is perhaps a comment on the growing dissatisfaction of many Americans during the 1960s.
Martha's dissatisfaction with George lies more in the fact that he actually loves her, than the fact that he's failed in life.
George and Martha's deepest dissatisfactions are reflected in their conflicting descriptions of their imaginary son.