You beat me to the punch. The first step toward stopping a destructive behavior is recognizing it.
People can't change how they think or behave unless they're aware of how they think and behave. Most people don't start out choosing how they behave - they behave "naturally", in the way that they've been brought up by society to behave. The don't consciously decide to think or behave a certain way, it's just what they've come to understand as being "normal".
Getting them to actually think about how they behave, to question why they behave that way, and to ultimately make the active decision to behave differently is the only way people overcome these deeply ingrained problems.
Unfortunately, there is a very strong reflex to shame and shun people for negative behavior - as if alienating them and making them miserable and defensive is going to somehow grant them an epiphany and let them see themselves in a truer light; as if negativity can somehow breed anything other than more negativity.
The strange, sad fact of humanity is that it is far too easy for all of us to hurt others who have done wrong, and perpetuate the cycle of blame and hatred. If we want meaningful change, we need to somehow find the strength to forgive them, work to heal them, and help stop the wrong from ever happening again.