This article is interesting but somewhat misleading, to the point that I don't know what information to trust. Yes, it does take many steps to turn cassava into a refined flour for baking, but cassava is easily eaten--just peel and boil it, as I do often (it's readily available in many grocery stores in Canada, and a staple of Latin American culture). Cooking is the same basic process used to make many borderline or poisonous foods edible, from bitter almonds to kidney beans. The author appears to conflate some specialized regional cooking techniques with simply making food safe to eat.