I think if you get right down to the nitty gritty until you reach the bottom line , its not about culture or religion.
In my opinion , as with many things in life it devolves to money and wealth.
Those coming here in rubber boats are mainly attracted by the idea of bettering themselves and their situation. 90% of this percieved improvement involves money and the opportunities to aquire it. The other 10% involves moving to a safer more stable envirinment that facilitates the former.
Those who are strongly opposed to the influx of illegals are against their tax money being spent on people who have not made any financial contributions. They feel that that money should be spent on improving the lot of native born people. Better housing , a better NHS , more help for the homeless , equity for pensioners regardless of where they live etc etc. There is also a small minority of racists and bigots
For those immigrants who succeed in settling in the UK , it is understandable that they prefer their own religion and culture. Some of these people can maintain these yet still succeed in integrating into the greater society. The Chinese for example. Whatever they may do at home and whatever language they speak , when going about their outside business they behave ' as the Romans do ' They do not need to live nearby others of their kind but are content to live anywhere and open up a takeaway. Other immigrants do not wish to do this , prefering to have a society within a society. This even happens here , where you see lots of westerners gravitate to places where there are already many westerners.
Personaly , I do not see any solutions. If today was like yesterday , tomorrow will be like today.