There is truth to this but it is also much more complicated. A lot of the doctors who were overprescribing - not all, there were those in it for the money - also didn't wake up one day and think that's what they wanted to do with their medical training. They want to help patients to the best of their ability, but when a patient can't afford proper treatment for an underlying issue, pain management is often all that the doctor can offer. And as LuvsOrlando pointed out, efforts to "solve" the overprescribing issue without dealing with why it developed in the first place has only complicated the problem further. Then, of course, there's the fact that once people develop an addiction, access to treatment depends on stability and resources few addicts can maintain.
The whole situation is tied into our broken, for profit health care system in so many ways, but because of those ties, I don't real expect we'll ever see meaningful solutions.