I haven’t seen a realistic Hollywood portrayal of an average American family in the last 20 years because the secular corporate culture is so willfully ignorant. This is argued as being a feature of interesting content though since ‘nothing average is interesting’.

It has skewed perception, but whether that matters is up for debate.

What would a realistic portrayal of an average American family look like to you?

This seems like an odd take to me. What is the point of film and fiction if not to see and experience things you otherwise cannot or would not?

The question I have is what is being preserved by not having a diversity of backgrounds, ethnicities and belief systems in films?

The parent seems to be suggesting that he doesn't want the emphasis to be on diversity, but rather on quality of characters. This doesn't imply that the characters have to be homogeneous.

Having "diverse" characters does not automatically make a movie more interesting. In fact, if you are relying on demographics (religion, race, sexuality) alone to make a character interesting, there is a very good chance the characters are flat, boring, and lazily written.

Of course having diverse characters does not automatically make a movie more interesting.

But interesting movies can be made about diverse characters as they can about homogeneous characters.

Only depicting homogeneous societies furthers ignorance and demonization of people who are different.

Showing more diversity, in interesting, authentic, and deep ways is one an important way we have of striving towards a society where we better understand and value one another, and get along.

> Only depicting homogeneous societies furthers ignorance and demonization of people who are different.

I think you're arguing against a straw man. It seems pretty clear that no one is arguing for less diversity, but rather against diversity for its own sake or prioritizing it above all other concerns.