Re: Classification
It's a way to allow people to avoid thinking and avoid understanding people. If you can label somebody then it allows people to ignore their concerns (or anything else they say easily) because "they are from group/tribe x, of course they are going to say that".
Politicians love and encourage this because, well. Divide and conquer. There's lots of votes in creating arguments and discontent by promising one group that you are going to screw over their fellow citizens. The more groups that exist, the more arguments that can be stirred up and the more futile and impotent each group becomes.
In the 21st century in civilised societies comprised of people who from a historical standpoint are almost unimaginably well educated and informed it is of course unthinkable to sit down with all of the groups, address all of their concerns and come to a sensible compromise.
But why is it unthinkable? Politicians. And you. If you let them get away with it then you share responsibility for the situation.
Of course, we could end it. Easily, even. Just promote tolerance, understanding and a dislike of politicans.