Can't say I agree with the sentiments above, and some of them are unhelpful.
Some groups can live side by side very productively and get on. The Sikhs generally don't want to start interbreeding with whites, but are happy to socialise, celebrate and otherwise fully participate in British life. The same can be said for Catholics, Jews Buddhists, Cypriots, French and many more. I have noticed in particular a higher proportion of Sikh men in particular than other groups signing up for the British army, and hats off to them for their bravery.
Not every migrant community is a problem. Its hard enough to convince danger hairs that Militant Islamism might actually not be the progressive tonic they need without complicating it further.
My Jewish neighbours give me no problems. Neither do my Hindu, Buddhist, Atheist or many of the others.
There are some who are unwilling to peacefully coexist. Even if you disagree with me and think everyone bar pure saxon stock should be deported immediately, you can see the merit of not picking a fight with everyone at once surely?
Especially when those people usually dislike the same sections of society that you do.