Ethnic Cleansing

As far as we're all concerned, Ethnic Cleansing is banned. Period.
But I can't help but ponder the reasons behind it being banned. Well, IIU does produce critical minded graduates no?
First of all, what do I mean by ethnic cleansing?
Basically, ethnic cleansing is the elimination of an unwanted group from a society, as by genocide or forced migration.
The phrase "ethnic cleansing" may embody just the opposite. Ethnic cleansing has been defined as "the elimination of an unwanted group from society, as by genocide or forced migration." This definition is inherently broader than that of genocide alone, and thereby encompasses mass killings and forced removals in far greater number and scope. The U.S. State Department, in a recent report on Kosovo, concluded that ethnic cleansing "generally entails the systematic and forced removal of members of an ethnic group from their communities to change the ethnic composition of a region." The latter definition, while accurate for that particular situation, is seemingly too narrow to be a useful descriptor of a majority of situations which are encompassed in the broader definition. Ethnic cleansing, then, may involve death or displacement, or any combination thereof, where a population is identified for removal from an area.
Determining what constitutes ethnic cleansing isn't really a problem.
The fact that it's a war crime and it goes against Chapter 7 of the UN Charter is no issue either. Every one is clear on that.
What really had me going was, HOW DO YOU DETERMINE WHICH GROUP TO BE ELIMINATED?
Is it because of the religion that particular race practices? Then which religion should be allowed to live? Is it because of skin color? Is the world really "spoilt" and "ruined" by any other shade of colour apart from WHITE? Is it because one particular group prefers same sex relationships? Who knew homosexuals can taint a society. Not that I'm saying the Quran allows it, I'm just saying, there are better tacts to dealing and helping homosexuals than to strictly condemn them.
Think of it this way, when one looks at those of a different group than they are but are good people, one is forced to question ethnic cleansing. Just because of a few bad apples, it doesn't mean the whole religion/race/etnicity/group is bad. Just because one Muslim believes jeans are illegal doesn't mean all Muslims are terrorists.
I see why ethnic cleansing is not allowed. If it were, we'd put an end to everyone, even the cherished gem kind of people, just because of their stereotyped group.