I don't deny he was addicted to painkillers at certain times in his life, e.g 1993 when he went to rehab for it. There is however no evidence that he was physically addicted to anything in the year before his death. It's just a huge misconception. The drug that killed him is not addictive in any way close to the way opiods or benzodiazepines are and there were no painkillers found in his system when he died.
If he had become an addict again before his death, why was he using a very expensive and very dangerous hospital grade anaesthetic? And why would he pay a doctor $150,000 a month for this service, when he could probably go to any doctor in hollywood and get himself some Demerol pills for a fraction of the cost. It shows that Propofol was something he was desperate for because of the purpose it served i.e. enabling him to sleep, rather than because he was a junkie wanting to get his kicks.
Sleeping pill addiction is very serious - and an addiction full stop. Whether he was desperate for the stuff to help him sleep or get high, the fact is that he was dependent on it, which means he was addicted. Doesn't matter the reasons - addiction is addiction.
You seem to have a very skewed idea of drug addiction and that one can only be addicted if they are a junkie rifling through bins for a fix. Addiction has many guises and MJ was a hopeless addict.