Ah, that's an interesting detail (one I agree with) - thank you for pointing that out.
If you need to force people to promote / accept your culture, you should be asking why people prefer other cultures and address those issues instead.
Need is too strong a word. Want is the word. And mostly its there to force content publishers to protect a culture - given the balance of size of American popular culture, American content providers, etc .. I think it's naive to think it comes down to "a free market would accurately represent the desires of a specific domestic market in which it operates"
Media/culture is not some giant buffet where people walk in and just take (and pay for) the plate they want.