Cuda, I think you've got a point in that rehab isn't going to work anymore than any other program if you don't really want to work at it. The desire, the [I]need[I] to stop drinking has to come from within, as you said. After that, how you get there and stay there...well, I think different things work for different people.
As I mentioned, I have never been to rehab, but I have supported two dear family members through rehab in the past five years. My best friend is now 2 years sober, and as you said, is continuing with a program after 8 months in rehab. She got a lot of good counselling there which helped her deal with some of the issues that helped fuel her need to escape reality. On the other hand, my aunt was no sooner out of rehab (for the 5th time) than she was back at the bottle. She's dead a year.
It all depends on what's within, I think.
Thanks for pointing out that rehab is not an assembly line for "happy shiny sober people". It can work though.