Rage is by definition abuse. Ragers react to strong emotions with rage. (i.e. feelings of  fear, sadness, shame, inadequacy, guilt or loss convert to rage.)

Ragers were typically shamed or punished by their caretakers for expressing emotion when they were young; i.e.: "Be a man and don't cry", "Nice girls don't get angry" or "I'll give you something to cry about". 

Raging gives the rager a feeling of power - offsetting their shame and feelings of inadequacy.

Rage sets up a neurochemical reaction in the brain that can be addictive, producing what is known as rageaholism or ragaholics.

Screaming, physical expressions of anger, violence or threats of violence, sulking, manipulation, emotional blackmail, silent smoldering, and anger used to punish. 

Healthy expression of anger involves confrontation of what makes you angry and an effort to set  boundaries. (What you will do in response to what makes you angry.)   

i.e: When you (a behavior), I feel (a feeling) , and to protect myself I will _________.  

Healthy anger is not used to punish, is not violent, and isn't used to intimidate, control or manipulate. It is expressed, discussed, and moved through.

Healthy anger is not stuffed down and ignored. (Stuffed anger created resentment and a wealth of physical / mental and emotional problems.)   Healthy anger is not expressed in passive aggressive and manipulative ways.

Anger management is critical to recovery from addictions and trauma, childhood sexual mental or physical abuse, and relationship recovery.  Addictions are in part a coping mechanism to deal with feelings by masking them.

Alcoholics and Addicts often "use at" the source of their anger. (i.e.: I'm angry at ______ so I'll have a drink, take a drug, or act out sexually.  Obviously this is a highly self destructive response to anger.  

Unexpressed anger related to childhood abuses often results in addictive problems later in life. (To stuff down the feelings of shame, anger, isolation, fear, sadness and loss the abuse creates.) Very often chronic relapsers in recovery programs, or chronic addicts are survivors of childhood abuse.

The sad irony is that by pushing feelings down alcohol and drugs make it impossible to work through our feelings and move past them, keeping the survivor trapped in a downward spiral.  This is part of why even moderate drug or alcohol use in non addicts severely compromises their progress in therapy. (If you are stuffing down your feelings how can you work on them?)

Regarding anger, the Big Book of Alcoholics Anonymous says:

"It is plain that a life which includes deep resentment leads only to futility and unhappiness. To the precise extent that we permit these, do we squander the hours that might have been worth while. But with the alcoholic, whose hope is the maintenance and growth of a spiritual experience, this business of resentment is infinitely grave. We found that it is fatal. For when harboring such feeling we shut ourselves off from the sunlight of the Spirit. The insanity of alcohol returns and we drink again. And with us, to drink is to die.

If we were to live, we had to be free of anger. The grouch and the brainstorm were not for us. They may be the dubious luxury of normal men, but for alcoholics these things are poison."