Nice of you to acknowledge my diet as "a perfectly valid choice", Brian..lol. A "typical" vegetarian diet such as I ate before D is not great for blood sugar control as it usually includes a lot of carb heavy choices such as rice, pasta, grains and fruit. However a vegetarian diet modified for reduced carbs, where low carb vegies are a significant part, is as good as or better than that of an omnivore.
In addition, there are many aspects of "health" and a "healthy diet" other than blood sugar control, as we all have other physical needs and issues aside from D. I won't even get into what is healthy for the planet.
My niece who was a vegetarian from a young age and my inspiration to return to vegetarianism after many years away from it is now an environmentalist and has returned to omnivore eating in the belief that it is a part of the natural order (which she could explain better than that). At first I felt a bit betrayed by this, but then sought to understand it, which is a step beyond "always respecting personal choice". Hence my caution to PWD's who ask me if they should "become vegetarians". It also helps to be understanding of others' choices when you get old enough to have made some of those choices at different times in life.