I don't think Moyers is perpetuating a misconception here - I think he is addressing one. It is difficult for anyone to draw the line between enabling and support, and I think that sometimes, people interpret the concepts of detachment and letting go as another means of control - I will detach, go 'no contact' so I can help my addict hit bottom, and in that way, I am pushing him towards recovery. We are codependent, after all; we are inclined to try to control our addict and the disease, despite the Alanon mantra.
It is very difficult, I think, to let go without anger, to detach without an undercurrent of retribution, because by the time we get to that point, we have been hurt repeatedly by our addict. I think it is important to remember that when we decide to let go, to detach - to perhaps even go no contact - we are doing so for us, to protect our health and sanity, and not because we think our behavior will influence the addict. If we are doing it to have an impact on the addict, then we are just doing the same thing we always do - trying to control our addict and his disease.
I think the article is helpful in pointing out that detachment doesn't necessarily mean no contact, and some support is OK. I think those who love and want to help an addict in their lives often struggle with this. That being said, I acknowledge that there are times when no contact is necessary for self-preservation, and I would never be critical of someone who makes that very difficult and painful choice.