Why Discrimination in the US is positive?

[Teddy Pollins]

I am not trying to insult somebody.
I have immigrate to the USA from Europe a few years ago, I find the concept of positive discrimination baffling. In the UK we don't really follow the concept much if at all but here in the US South it seems to cause some bitterness.
I find the concept of positive discrimination to just further work to separate races and focus on differences rather than to just focus on being 'People' rather than races.
Why the thing doesn't work at all?
May discrimination improve our society?

 

[Vigilante]

You must learn that there are many high placed officials, and supposed civil rights leaders that make their living out of fermenting hate between the races!