We went vegan because my wife's sister, who was a professional triathlete, and is still elite level, had an operation for a 90% blockage in a carotid artery. Her doctor advised going vegan to cut out all animal fat. With additional family history of the same, my wife felt it made sense, so there we are. In addition, eating that low in the food chain cuts about 70% of one's carbon footprint. As mentioned above, some are boorish about being vegan, but certainly not all. And as proven above, some are simply boorish for God knows why.