A Culture is a value system - Kaos1973

So multiculturalism is a multi value system. Different values require different rules to enforce.
When we play a team sport it is necessary for every team member to hold the same values and abide by the rules.
Imagine trying to play basketball whilst some in your team are trying to play ice hokey, others ping pong and 1 polo.
It is not going to work.
It is even necessary for the opposing team to follow the same rules otherwise why would you waste your time playing a team that cheats or changes the rules to suit themselves?

Some people conflate ethnicity with culture.
Your values or rules are linked to your ethnicity but are not completely determined by them.
Even as far back as the Roman empire this was acknowledged in the saying "When in Rome. Do as the Romans do".
This is because where multi ethnicity works, multiculturalism doesn't. Only a mono-culture or single set of rules and values works for any team sport and the ultimate team sport is the human race. Your teams are family, community, country.

Learn the rules, play the game and everyone wins.