Well a few things to consider.
Suarez does not contest the fact that he used the word. He contested that the word can be used in a non-derogatory manner (kinda like how black people calls each other the the n-word.
But the fact is that he and the other player is trash talking each other it was very heated. The word was used more then once, so any logical person will have to conclude that is not used in a friendly context, and that he was racially taunting the other player.
This doesn't mean Suaraz hates black ppl (LFC's rather pathetic defense of Suarez having black friends and a black grandpa seems to miss the point), it merely means he is using racist language to try to wind up the other player, which is still unacceptible and deserves the band.
John Terry is charged now, it would be interesting to see how it turns out.