For my recovery, I don't care whether it is a disease or not. I only care whether drinking causes misery and problems in my life. If so, I need to quit.
Aside from that, there are plenty of "real" diseases that are caused by lifestyle choices. Lung cancer is no less real because it was caused by a choice to smoke. Diabetes is no less real because of choices made about diet and exercise. Where alcoholism is different is that the cure (or whatever it should be called) is 100% choice. The brain can be wired to create extremely compelling urges for certain things. The American restaurant industry has pursued this relentlessly by adding fat, sugar, and salt to their offerings. So is it a disease if our lifestyle choices rewire are brains to have unhealthy cravings that only our future choices can overcome? I don't know, but I do no know there are real physical changes that occur that make making the decision not to drink much harder than in other areas of my life.