Immigrants don't have to completely conform but must have respect for customs, laws and traditions, want to be there and try to generally assimilate. Not trying to make the new country look like their old one. Some areas of London (east London) and Paris look more like the middle east than Europe. What bothers me is when confrontational radical middle eastern leaders try to force Sharia law into the new community, that is completely unacceptable.
Diversity in the sense that not everyone needs to look the same, act the same way in their homes or have the same religious beliefs but need to respect the customs of that country.