I just made it softer (though I never mentioned race but economic migration), still can be too sensitive so let it be, just my opinion (I am in Eastern Europe and there the views are rather harsh, compared to Germany or France or Sweden)
You havent said anything wrong about immigration. People who misunderstood you are racist themselves as they have dismissed cultural issues of your country and tried to impose their own views. So dont listen to them, they are just ignorant at best.