> What if a diabetic wants a cookie? Or ice cream?

Diabetics can eat cookies and ice cream, they just need to shoot themselves with insulin afterwards. It's having too much of it the problem.

Besides, if something is bad for you, you avoid it. Period. There are infinite other flavors in life to make it all about that single one. "But I want it" is not a reasonable argument.

Aspartame and most sweeteners fall apart at high temperatures, limiting their usefulness for a lot of foodstuffs, like cookies.

Which is a shame in my opinion.