The problem with artificial sweeteners is that in great quantities some have been considered or proven toxic. When people drink 2L (two liter) bottle of Diet Cola, for example, there is risk that the body is being overloaded with artificial sweetener chemicals that can cause brain damage, CNS damage, or other problems. Regular non-diet Cola only has sugar and flavors in it, which may be healthier than artificial sweetener. Better choice would just be some cranberry juice or orange juice, but that's another story.

Aspartame or similar artificial sweeteners are not severely toxic when taken in very small amounts. However if you have one or two liters of diet cola, and if snack foods you eat throughout the day have more chemicals in them, then you are really bumping up the amount of chemicals passing through your body which can cause brain damage.

Stevia is more natural. There have been some possibly false reports out there that stevia is unhealthy.

Stevia was even banned from being sold in countries. Why not Aspartame too? If large amounts of Aspartame are damaging to humans, and if it is questionable whether or not Stevia is even toxic in the first place, then why was Stevia banned and not also Aspartame?

Was it chemical companies needing to make their Aspartame profits? Or is stevia really toxic?

Or are companies just too lazy to extract Stevia from plants, since that is too hard to do in their chemistry labs? Will it not make them millions of dollars like Aspartame will?