Quinoa has thousands of years of history as a staple crop with no known health issues. Its protein content is considered optimal by contemporary medical advice on vegetarian dietary needs. I recall reports of it being able to sustain health in extremely limited diets better than other cereals can - make of what you will, I don't expect those reports were fabricated by alternative food fad scammers.

At the very least Quinoa seems a fine (and tasty) staple grain to increase variety with - an aspect of diet which is very widely advised as a positive thing.