Why do some people oppose the influence of American culture on their society?

This is so, primarily because of what is called 'cultural
resistance'. American culture or Americanism is looked upon as heterogeneous, having no
clear unified identity. That's the reason why many tradition-bound societies find
American culture and cultural standards suspect. America has been a land of all nations
and races, highly urbanised and technologised, with supposed moral  libertarianism, an
epitome of socio-cultural amorphisity.

The oldish,
traditional societies, trying to stick on to their nativist/nationalist beliefs and
practices, tend to ward off whatever is American. A bit too frank & open, too
independent American life is not acceptable to many societies.