Hey OT, I've read through your post several times and really have no arguments with it. All seems to be very sound reasoning on a macro level.
But let's switch the focus to a micro level because that's what I think this whole topic is about. (Forgive me if I'm wrong, MTO). We are watching family members/friends/loved ones pi$$ing their lives away because they are caught up in a cycle of addiction to whatever substance. For me its the most sickening, helpless feeling in the world to not be able to get through to them what they are doing.