Bryank, you are outlining an ongoing argument that probably won't have a resolution anytime soon. I've read a lot lately about the new scientific evidence of the effects of addiction on the brain, and it is quite fascinating. But as ru12 says above, it boils down to simply semantics for those of us dealing with it (whether directly or ancillary).
I spent a lot of time educating myself to substance abuse - and in the end it didn't matter what I knew about addiction itself, but what I learned about managing my life in the face of addiction. What I learned about my husband's "disease". What I learned about myself. I hope you find the same amazing experiences in Al-Anon - keep going back!
Cheers,
~T