Our member dietitians work in a one-on-one relationship with their patients and they may recommend aspartame-sweetened products for a particular person if they feel that perhaps they're drinking a lot of pop and it would be better for them to reduce. It may be part of the considerations, and as Dr. Hutchinson said, it is safe.
However, in terms of a general public recommendation, it is true that it encourages the sweet taste and perhaps there are better options for drinking. Water and milk are certainly better options.