The world would be a better place if there wasn't multiculturalism. I'm not being racist - it's a fact.
Look at Italy, France - most of Europe - there's just so many races now, which is causing major tensions. I know because I have family there. Many of these immigrants will work for half a "white-mans" wage.
You obviously don't have much experience with rental properties and different groups of people either. It's stupid to let anyone into your rental property just because you want to give everyone a fair chance.
Londoners were in their country first - they have the final say.