Why is it called "reverse discrimination"?

I always found that term offensive, that is, "reverse discrimination." It seems to imply that there is a right way and a wrong way to discriminate. It is always the "wrong way" because it is bigotry and prejudice that causes it.

The Human Rights Commission (HRC) this morning confirmed receiving the complaint of racial discrimination submitted on 24 December 2009 by the human rights initiative, AfriForum, on behalf of two students against the Table Mountain National Park. The complaint followed after these two students had been refused accommodation at the “People’s Trail Hut” because they are “white”. http://bit.ly/6EnHz3

This is a good example, in fact. And you will see in the article that the people who were doing it, that is, denying white rights, were even doing it wrong, according to their boss.