I don’t really think them quitting on their own is what Nedak is saying. If I’ve read his posts correctly; I believe he is implying that you cannot force someone to quit. All you can do is try to keep them alive long enough until they decide they want to quit. Then you can help with drug rehab. In my experience with family members that was the way it was. We tried the interventions, put him in rehab (all that did was waste a lot of his parent’s money; he was high again within 3 weeks of getting out). We tried the incarceration (all that did was teach him to use different drugs and made it easier for him to find drugs). He finally quit, but only when he decided he wanted to quit and that was only after he forced his parents into bankruptcy because of the cost to put him into rehab 7 times.
A small glass pipe is a little cheaper than wasting money on imprisonment or drug rehab when all you can really do until they decide they want your help, is try your best to keep them alive.