I think flowgraphs alone don't make non-programmers programmers, although they might take about 30% of the handicap to write code away. It might be still needed to have some code prefabs, which bring the expertise of programmers to the hands of artists, and they can access those prefabs via flowgraph entities.
Even if people know a language, they don't necessarily know logic. Logic has has nothing to do with any language, but it must be learned seperately. Often the lack of understanding logic is seen with younger people, as it comes with life experience also, so for older people understanding and developing logic is almost trivial.
Code prefabs can bring also the logic to the non-programmers, as they still would understand abstract high level logic, just not in-detail logic with all their if-then, flags, timers, and states.