It's like learning the relative value of a poker hand in terms of being politically correct. I'm not familiar with the situation other than what I've read here, but apparently threatening to kill someone(other than the President) isn't looked upon as poorly as insulting someone based upon race(and probably sexual orientation, although it is likely more ok if the insults were to fat people, hippies, Tim Tebow, etc). The coach may have had good intentions in his heart and this may be overhyped, but it is a result of the media purposefully creating racial tension where it need not exist.
The night before last, I watched my favorite Clint Eastwood movie, Gran Torino. It did a good job of showing how speech needs to be taken in context. People make fun of each other based on differences, and obviously race is one of the more glaring differences, and is easily incorporated into an insult in the heat of the moment. Id like all folks to avoid insulting each other for any reason, not just the ones that the powers that be choose as special. Regardless, the coach may have had good intentions, but certainly not good delivery. When I was a child, there was a saying that 2 wrongs don't make a right, and I think it'd fit right here, although I'm not familiar with this story other than the posts I read here. I haven't read what the kid said to draw such hatred(or if he had been provoked, like the SU female soccer player before that start of the season). Did the kid end up getting banned like she did? Anyhow, the kids, the coach, public reaction to different aspects, are mostly reaction to programming that creates a strong emotion.
A lot of this is just the usual BS where someone takes a side to make themselves feel superior to the object of their derision. In this case, based on my very limited information, my first take is that both the kid and coach were in the wrong. The Rodney King incident is an example where both sides can be in the wrong and yet each gain supporters when the media gets involved. In turn this reminds me of US politics, determining which evil is the lesser of the two. Was this far beyond the trash talk in playground hoops?
The whole thing reminds me of a time I saw a young child fall down, and then look around to see if anyone saw it before he started to cry. I've been told this is not uncommon.