This is a very common failure. Marketing did the survey (and heard strong interest); clinicians developed the program (which did not meet the expectations). Why? The clinicians designed the program according to their own perception of patient requirements, according to their own capabilities, and according to their own expectations of what a "good outcome" looks like. Customer input was ignored.
Have you never heard an ad that said, "You gotta have it!"?
Now, when the implementation team includes marketing people, at least the requirements might get implemented. Better yet, when the implementation team includes customers, the outcome is more likely to be accepted. And, best of all, an implementation team that includes representative stakeholders mitigates the risk of failure.
Many projects benefit from doing a prototype (a small likeness of the product or service) that is designed to be thrown away. This gives consumers a chance to react to the concept without actually changing. Then, adjustments are made to the Scope Statement, and another, better, concept is presented. A spiral development process keeps costs low, manages risk, and maximizes customer satisfaction (note: this is one reason why you hear so very many "leaked" announcements before a product is marketed).