I think you're the one who owes me an apology, WAV.

You write:

when people lose their own culture, society suffers

and

trying to have a multiple number of cultures living under the one state law will always be problematic

So everyone should have a culture of their own, but there shouldn't be more than one culture in each nation. Foreigners shouldn't bring foreign culture to England (too many cultures) and they shouldn't assimilate (and lose their own culture).

Or, as I said, You want fewer people with the wrong kind of suntan to be allowed entry to England's green and pleasant land.