I don't think the way people see multiculturalism today is correct. I think multiculturalism today is basically the same as a melting pot, which also doesn't work or rather, if it does work, it comes with massive social disadvantages and social strife as different people, in an effort to gain some identity as a group, maximize superficial differences versus substance differences, so superficial differences become "oh so important" while the real kind of differences, substance differences, become irrelevant or undesirable all together.
To give an example of what I want to say. If you as a multiculti moron today, what is more diverse? A group of 5 people that are all of different races or a group of 5 people that are all the same race, he'll say: the group that is of different races ; because that is in his mind, the diverse one, and that is superficial differences. the correct way to go about it is to ask "well what do each of those people do in each group and what do they believe in?" And then I can say: Well in the one of different races, they're all 5 people of different races but are all web designers with the same training and aptitude, atheists and socialists (let's say) but in the other group of one race, each of them is a doctor who is a christian and a liberal, the other is a mechanical engineer who is an environmentalist, the other is a psychologist who is an atheist, the other is a electronical engineer etc. You get the point, people of different backgrounds, truthfully unique in all their opinions and knowledge who can complement one another and have some interesting dicussions. Those would be the group I would rather be friends with or go out with a beer with. ofc, this is an analogy, a metaphor for what I am trying to say.
So the first group is a multiculti dream because multiculti people are idiots, the 2nd group is the correct form of multiculturalism in the sense, that diversity is good but the correct kind of diversity. You want to have diversity with substance behind it, not just for show, not just for flash. When you do that, you get the wrong kind of multiculturalism, what I call multi-culti because it seems like a fanatical cult that worships multitude for the sake of multitude. And you get tensions and you get social strife and radicalism on all sides because that's just what you get.
Now John Cleese isn't someone I care about when he isn't doing comedy or bashing americans for their silly belief that american football is actually football... so that's why my comment is not related to his comment. It's just my opinion on the whole thing about multiculturalism. You find multiculturalism everywhere in the world, the world is truely a multicultural place but you don't experience another culture by importing people who contribute nothing to their culture en mass. People who do gap the cultural bridge and enhance both societies by doing so are people who have an affinity for their own culture. So great chefs, artists, poets, writers, comedians, all the people who have an affinity to their own society where they were born and raised in, and can attune to the new one they moved to and bring some of their talent and put it to good use.
In other words, if you want to eat indian cuisine, you don't import 1000 indians from India, you bring just 1 who can cook good indian food and have him open a restaurant. Ofc, I don't know why you would want to kill your toilet on a regular basis but w/e, to each his own.
Same with chinesse food, not fast food chinesse food, the other kind. Import a few people who know how to cook it properly and they'll be successful and bridge the gap between nations and people. And more so, if you want to experience the whole chinesse culture, don't import 1.000.000 chinesse, go to China and experience the real thing, the whole package and take in as much as you can, then come home, and tell your friends how fascinating it is. And as more and more people go to China and experience Chinesse society and all that, and as Chinesse grow more familiar with your people, a relationship of trust and friendship and mutual benefit is formed and when people of some artistic talent travel, they bring back to their society more than you and I can. Tourism, traveling... these are the real and only ways in which culture grows and enhances and in which people understand one another better and form better ties and things grow. Not mass immigration of the plebes.
Now ofc, those are exotic examples. Europe is blessed with dozens of unique and varied and intersting societies and cultures and for centuries it has been under the correct way of multiculturalism. That's why you had artistic currents flow through all of Europe, bringing unique expressions of themselves in each nation. The Baroque is different in Italy than it is in Spain or in England. The Romanticism current has brought many literary and poetic geniouses to bring to life countless works of art that defined and enriched each nation and people... etc.
A lot to say...
tl;dr: multiculturalism as it is practiced today is BS, it's not multiculturalism and it's mostly bad, it's multiculti nightmare. Multiculturalism, the real thing, has always existed and is an organic process and it doesn't destroy or shallows a society, but enriches it. Cornershop culture (bunch of people isolating themselves to turn their neighborhood/street into a ghetto) is detrimental and only serves to create social disharmony and tensions and needs to stop.