In all honesty, the fact that he had been an upright taxpaying citizen to begin with... good job, house, car, friends etc., was an excellent incentive to break the habit.
My stepbrother is in his late 30's, has 5 illegitimate kids, no job, no car, and has never held a driver's license. Oh and he's a heroin addict and all his friends are meth heads. Why doesn't he quit? He's lived in the same house virtually his entire life, in and out of jail and prison, and his dad essentially allows him to live there as a daily fuckup.
DeLancey Street is an excellent court appointed 2yr alternative to the courts themselves. You can also just walk or drive in right off the street if you have the balls. Problem is you have to willingly enter it (the hard part), have no outstanding tickets/court appointments, and show up sober. Even so, I've seen guys with 4 years under their belt, walk out the door and OD within a week.
It really boils down to the individul themselves and the choices they make. Guys with 30+ years of addiction do not normally survive it. It just eats them alive, if not slowly.