Is it type 1 or 2? If it's type 2, have him look up Dr. Fung on youtube. He lays it out. Basically it's keto and fasting. I personally know people who were lifted out of type 2 diabetes by following Dr. Fung's protocol. All the best to him.
I'll answer #2. I don't know that it's "growing," but yes, I do believe there is a significant subset of people on this board who, in my opinion and experience, do not question things enough, or maybe at all. This is proven daily by the many posts that have X and other links or are simply a photo, article, graph, etc. that purport to offer XYZ as fact, but offer zero accompanying sauce. I have mentioned this a few times on the board, myself. And I have commiserated with other anons about the problem, privately.
Is it laziness? Is it that they are too trusting of what is posted by fellow anons? No idea. Bottom line, it's a failure to use critical thinking skills and to verify for themselves. Did Q fail? No, I don't think so. There are many who DO question and research. Perhaps, eventually, the others will join. My two cents.
If true, let's hope their house has better judgment.