Why is it so wrong?

I was at school and I heard my friend Harrison say the r-word. When I told him not to say it, he asked why. I wasn't sure what to tell him, so I told him that it was disrespectful and mean even if he didn't mean it that way. He hasn't said it in a while and I'm proud I could help him and others understand. Another time a new kid at school said the r-word and I told him not to, and when I gave him reasons he just didn't get it. That night I sent him about five articles expressing how it felt when the r-word is used. After that he stopped, and the next day apologized to me, saying that he understood. The other day I heard him tell another student not to say it and I gleamed with pride.