[wrp]

> Why do they keep inventing new sweeteners...

Because nothing so far tastes as good as real sugar. The common practice in employing artificial sweeteners is to combine two or more in an effort to avoid the bitter aftertaste that you get from relying on just one.

[irthomasthomas]

More likely it's because they cannot claim their product is helpful to dieters, after there is mounting evidence that it may actually be worse for them.