Multiculturalism is the new fad. Actually, it's more like a religion. Diversity is practically worshiped like a god. To not be all-inclusive is a sin. The problem is, multiculturalism is an impossible dream. There is no such thing as all-inclusive.
Diversity is indeed a good thing. We need it in the realm of ideas, and we need it in the gene pool. The problem is, some ideas are mutually incompatible.
Cultures are meme1 complexes, that is, collections of ideas. The ideas in a meme complex are pretty harmonious. They have to be or they couldn't coexist. When people of different cultures meet, they share ideas. Sometimes, when those ideas clash, there is conflict.
You can run into trouble just by wearing the wrong color of clothing. Some colors are consider to be gang colors in certain areas. If you wear the wrong colors, you can be beaten or even killed. Some cultures don't like nudity and cover their whole bodies, while others flaunt it. Think Muslims in a nudist camp.
Sure, we can change our behavior. We can wear different colors or we can wear less revealing clothing, but their is nothing all-inclusive about this. We would be excluding ourselves and our culture in order to accommodate other cultures. Sometimes we have to make compromises. A certain amount of tolerance is a necessity. That's life, but too much tolerance is as dangerous as too little.