I see what you're saying, but what you said about long term legitimate users displaying addictive behavior is a fallacy.

A fallacy how? Where do you draw the line between addiction and physical dependence? Many people who are physically dependent also show a mental dependency as well and this becomes especially apparent if they are ever cut off of their medication.

You cannot compare that type of long term use to a n addict maintaining their addiction with no legitimate medical need for the medication.

Who determines what is a legitimate medical need? 30 years ago opiates were generally only prescribed to people who were near deaths door. It is only since the 90's that doctors have really started handing opiates out for long-term management of pain. What makes someones back pain more serious than someone else's severe mental anguish if they have both found relief in opiates? Who decides who is a legitimate medical user? What happens if two doctors disagree about a patient being a "legitimate" user? Who is right and who is wrong?