I agree, diversity is good up to a certain level as long as it does not cause too much conflict with the original culture and people.
I myself am from Japan, and for me to be able to live here I had to go through incredible amount of checks and prove that I had enough fund to sustain myself without relying on this country's benefit. This vetting system is becoming harder each year for Japanese and I guess for a lot of other countries. It is hard to understand that the country who has done such strict check on me is accepting immigrants so freely, knowing that it is obviously increasing the danger for the life of British people, and even offering houses, living expenses etc to them. If it was the case in Japan, I would hate it. Britain should select who it welcomes to the country and who can integrate to British society.