Some literary work should not be made by into films. Or more pointedly, until studios are comfortable producing and marketing all kinds of films - films with traditional narratives, films without - they should stay away from work like For Colored Girls.I think this may be a better articulation of the argument Mike is trying to make. It's entirely reasonable to argue that Paradise Lost has more in common with Alexandre Dumas' work than it does with e.e. cummings', and that Archy and Mehitabel, with its balanced dedication to the rigors of form and the demands of narrative lies somewhere in between.
There's no question that people who are doing narrative work are doing something different from people who are not. It may be that the form that work comes in is less instructive than the work's purpose, whether it's story-telling, descriptive, evocative, polemical, whatever. But I don't think that means we collapse all distinctions between poetry and prose. Perhaps we just realign them.