Why can't his films be more racially diverse

That's what keeps me from being a big fan of his work.

Because most of his films take place in Montreal, and Montreal is majority white.

I agree, this is one thing only that I don't like about his movies.

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Sorry for my English mistakes.

Actually there is a lot of ethnic diversity in Montreal...

I find that directors with ethnically diverse films pursue subjects in which diversity is a factor in how things play out yet most films I see aren't diverse at all. It's one group with one or two outsiders mixed in. I also find that many people don't care about diversity. It doesn't factor into their pursuits. Joel Coen confirmed this when stating that diversity doesn't factor into his casting decisions. He like many don't think "I need to change the color of this character so it's ethnically diverse." Even non-white ethnic groups don't think like that except for weighing in economic concerns such as casting Ewan McGregor to help Miles Ahead in the European market or casting Matt Damon in The Great Wall to help the Western market prospects.

Non-white ethnic groups lack the economic power to have genuine position in the film industry. Instead, white people who make up the majority of population of the U.S., Canada & Europe control all industries. True diversity will depend upon greater economic power to buy into the market and its affiliated industries. Beyond that, it will just be calls for diversity that will be treated like appeasement charity cases. This will be attacked as political correctness & racial quotas as it won't be fought for economically but given as a token of admission of white privilege, which a segment of whites will feel as being nothing more than white apology from liberal white apologists, which the entire group didn't agree to give to anyone. It will be greeted with backlash and resentment. This cued the rise of white nationalism and disregard for outlandish racism among the white working class in the West in 2016.

www.teriekwilliams.com

There's also a majority of whites...

Among stupid reasons for liking or not liking a film, racial diversity is one of the stupidest.