In the context of T2 diabetes, white rice is a high GI food. Brown rice, legumes and grains contain plant toxins and antinutrients which are poorly researched, but at least anecdotally can cause all kinds of issues especially in sensitive people.

Also, in the west, a lot of the culture of preparing these foods (such as fermenting or vigorous soaking) is bypassed.

> Bean consumption is typically a good predictor for survival in elderly people.

That data suffers from the usual issues related to nutritional studies. Consuming beans in place of donuts may be a good predictor of health, that doesn't mean that beans themselves are healthy relative to other healthy foods.