Why do not all use Splenda diet sodas instead of aspartame?

To my knowledge, diet Orange Crush is the only one that uses Splenda artificial sweetener. It tastes great! Why not others? In my opinion, is Splenda tastes better, so I do not know what to choose aspartame ….. could be the cost, though … Splenda is perhaps more expensive for corporations to purchase in bulk … Anyone else have input? It was approved by the FDA in 1998 Despite Aspartame and Splenda are artificial sweeteners, which are both DEFINITELY NOT THE SAME. They have a completely different molecular structure. Hense the difference in taste.

Cost.