Intercultural training for organizations: The synergistic approach

As Adler points out in International Dimension of Organizational Behavior (1997), global leaders tend to recognize the value of cultural differences but the synergistic approach is still much less practised than the parochial or the ethnocentric approach which is based on the assumption that our way is the only way. By synergistic approach, Adler means the approach to incorporate the values of all cultures involved within an organization. Why is there such a dilemma? What has hindered global managers from practicing what they believe in?