You know there are different types of diabetes right? Type 1 I absolutely have sympathy for. Type 2 (The one you must be talking about), not so much.
Like you said this is just something that we disagree on and that is cool. But let me throw this your way. I think that we both would agree that addiction and diabetes are for the most part preventable and self inflicted "ailments" (I use that word b/c you don't like disease for addiction, trying to be fair). So.....would calling diabetes a bonafide disease be a disservice to the word "disease" b/c its self inflicted and completely preventable by living a healthy lifestyle?
I hope this isn't too personal a question so feel free to disregard this, but if your brother succumbs to his addiction and passes, would at least a small part of you resent him for this? Think about it... Would you feel the same about someone dying of a condition that they actively played no part in acquiring?
Whatever your stance on it is disease, ailment etc....its a tragic, tragic thing that no deserves. The sad truth is that I will probably lose my oldest brother to this. And that is ****ing devastating thing to try and come to grips with.