Interesting summary. This is the line of reasoning Taubes presents in Good Calories Bad Calories also. It is also aligned with the observations of paleolithic peoples - they don't get metabolic syndrome, which is the vanguard for diabetes, cancer, heart disease and/or other vascular diseases. There's a good reason to believe this entire chain is caused by excess carbohydrate intake, and, for example, whether you treat skinny (type 2) diabetics or obese (type 2) diabetics, when you reduce their carb intake they respond with lower blood pressure, improved hyperglycemia, lowered triglycerides, increased HDL levels, and a lower A1c (and their LDL levels, which may get higher, will convert to large, fluffy LDL which are not associated with cardiovascular disease). In other words, change one variable - carbohydrate intake - and all the symptoms improve.
In short, you can treat metabolic disorder and arrest its descent into diabetes and progression towards premature death and drastically reduced quality of life by restricting carbohydrate intake, whether the sick person is skinny or obese. Makes a strong case to me that the carbohydrate is the causal factor in most of these cases.
Interestingly, the article leaps right into the possibility that metformin, a fairly mild drug used to help pre-diabetics with glucose regulation, would reduce the incidence of cancer by helping to retard diabetes and lower blood glucose and insulin levels. And I hope that is true, because it's going to be a number of years before enough people realize they could also save themselves via carb restriction. (Edited 1 March 11)