Multi-culturalism has been criticised with claims that it doesn't work because of the intolerance of different races, nationalities and religions. Opponents of multi-culturalism go on to state that we should embrace integration instead. Most people who ascribe to this opinion do so because of their own intolerance. Their idea of integration is for all other races, religions and nationalities to become the same as the host culture - namely theirs.
There are aspects of the host culture which will always be there and which everyone does integrate with. These aspects include protocols when shopping, working, catching public transport, obeying laws, interacting with each other in public places, enjoying national and local public holidays and so on. That is as far as integration needs to go. As a society we should be not criticising people for their cultural choices of clothes, food, worship, language.
The problem with integration is that it fails to accept the differences between other cultures. The integration argument reduced Christmas to a season of generic greetings and phrases. For instance, in Toronto a Christmas tree was described by the city council as a "holiday tree", other Councils replaced "Merry Christmas" signs with "Seasons Greetings" and used secular phrases rather than mention anything "Christian" in Christmas. This was done because of a lack of acceptance of the differences between Christianity and other religions. This secularisation of Christmas was seen as political correctness and was aimed at not offending other religions. Yet, most people from other religions have no problem with Christian celebrations and will often join in.
True political correctness would accept and celebrate the unique festivals and practices of Christianity, Islam, Judaism, Hinduism, Buddhism and so on. This is why it is so important to protect and embrace multi-culturalism, not reduce it to a generic "integration" in which the distinctions and characteristics of cultures are ignored and not accepted.
Some critics of multi-culturalism claim that other cultures do not assimilate well and that they have different values and morals. From the outset this argument is flawed. All races, cultures and religions have high moral standards. Every nation has laws to protect those standards. There is not a religion or race today that condones violence or abuse. On the other hand, every religion, including Christianity, every nation, including Australia, has individuals who violate the law. It must be kept in mind that these are individuals and they are not indicative of any race, religion or nation. The behaviour of individuals should not be used to judge the behaviour of all.
Multi-culturalism is not to be feared, it is to be protected and valued. Instead we should fear any society or government which attacks multi-culturalism as they are the ones on the path to an intolerant, totalitarian state such as we saw under Hitler or the Taliban. Multi-culturalism is not about establishing an "us and them" society. Multi-culturalism is not about creating multiple societies, it is about accepting that society is comprised of people from various cultures and that those cultures do have unique characteristics. We should not just tolerate those differences but acknowledge, accept and celebrate them.