You're right it does beg that question. I don't believe in the 'disease model' of addiction myself really (although I don't mind people using that word or 'illness' to describe the condition at all), certainly once you are clean and detoxed that shit goes right back to being a choice. I can buy that when in the throes of active addiction or when you are detoxing then there is certainly an element of your choice being removed, although I would question even that for lots of drugs. The situation might make that choice a lot harder but it's still a choice. I say that as someone who has detoxed from dependance causing drugs (as well as having been psychologically addicted to a number of non-dependance forming drugs as well) and relapsed again many many times. Like pathetically shit attempts at getting clean over and over and over.
I would say the more important question would be why the fuck would you bother going to a rehab where 95% relapse within a year and most during the first week unless it's for legal reasons? They're clearly a bunch of jokers with no real skill in rehabilitating people, why would you get involved with a project like that? There are plenty about with much better success rates.
Clearly you can't run a rehab where you are allowing people to use though, I don't see how you can question that really. You have to make the utilitarian decision and that is to create as drug free an atmosphere as possible, it might mean losing some people who need help but it will allow you help those who remain better and there is always another person to fill the space vacated.
All just my opinion of course...
Anyway, I'm not looking to hijack matey's thread here. This is not really productive discussion, or rather not the appropriate place for such rambling. Sorry TT! I hope you haven't given up and are managing to stay strong.