This is pretty similiar to your last idiotic post which I see has sensibly been deleted.
It kind of smacks of thoughts along the lines of maintaining racial purity and bloodlines. The last chap who made a big thing of that, Adolf something or other, came to a sticky end, so beware of your thoughts processes, they will hurt you in the end.
Also,I thought that the British were world leaders in the field of irony.
The fact that a post carrying on about assimiliation of cultures and slyly advising immigrants that maybe they would be better off in their homelands is daft enough.
The fact that the writer of this post is called "Brit-in-Singapore" is well, irony worthy of award status.
So finally, my thoughts on the issue you have raised:
One, you are just looking to stir up an argument based on bigotry and racism.
Two, you will probably do it again and again because its how you get your thrills.
Three, the vast majority of people on this board would find your views anything from slighty yucky to downright revolting.
I fall into the latter category.