This question about whether addiction is a disease or not is an old and ongoing issue. For families it can get in the way of them responding to this condition effectively. The bottom line for family members is this, whether one chooses to label addiction as a disease or a bad habit, the addict must take responsibility for their treatment/recovery in order to be able to make positive changes in their life.
This issue always came up in the family class. My response to them was that I chose to view addiction as a disease but that was not a requirement for them. What the family members needed to learn was that the addicted family member's behavior was the important thing to observe and respond to. The question of whether addiction is a disease or not disease becomes a distraction. It is more important for family members to learn what their own issues and strengths are so they are able to respond effectively to the addicted person's behavior for their own wellbeing.
If I were gong to use an analogy to show how addiction is a disease I would use diabetes, hypertension or some cancers. These conditions all have both lifestyle and/or genetic roots similar to addiction.
It is important for families to not feel they must label this condition. Family members and addicts are ultimately responsible for acknowledging their condition and taking responsibility for their own recovery.