> and it's at least as bad as sugar (at the very least in the public opinion / medias).

Shrugs, public opinion and media's opinion is just that opinion not fact so is (to me..yay my opinion) irrelevant.

Nothing is safe in huge amounts but I'll take aspartame over sugar as the risk of diabetes is known.

http://www.nhs.uk/livewell/goodfood/pages/the-truth-about-as...

I agree with you about the general opinion. However I do believe it is relevant to your first question which was why Coca Cola does not promote on it more, I don't think you want to advertise on doing something people dislike or think it's bad (be it true or not it does not matter at all).

On the other hand I think most people know drinking Cola is not good for your health.

There is no evidence that consuming a small amount of aspartame (less than 30 cans of diet soda a day) is harmful to you.