I don't watch entertainers who insult people. I've seen Chris Rock for a couple of minutes on a couple of occasions, didn't care for him, and either turned him off or left to do something else. When he came on the Oscars for that bit I hadn't made it out of the room before the slap, so I saw it.
I liked it.
I don't condone Will Smith, or violence as a response to speech, particularly when Will Smith was at an event where the comedians regularly insult the audience and everybody knew the insults would fly. On the other hand, seeing Chris Rock get bitch-slapped put a smile on my face.
Comedians who insult people for money play a dangerous game. They have to know that not everyone is going to abide by high principles of free speech and non-violence while they verbally abuse those around them. The comedian is always risking a beating, because that is what sometimes happens when you insult a person or the person's family. Ordinarily, he or she has hired protection, but this time Chris offended a guy who was of the same social status as he and his protection failed.
This doesn't excuse Will Smith. The law has to play itself out. When it comes to insult-comedians I will continue avoiding them. For those who like that sort of thing and want to protect and encourage those guys, go ahead. They will be protected most of the time. But not always. And when the protection fails, guys like me will be hard-pressed to conceal a smirk.