Dupree is a widely respected artist, with paintings in the Philadelphia Museum of Art, and the idea of booting him out of the struggling West Philadelphia enclave, where he mentors local kids, was counterproductive on its face. But the authority's proposed replacement, which had begun with the worthy idea of bringing fresh food to Mantua, was flawed six ways from Sunday: The authority had assigned the sprawling site between 36th and 37th Streets to a developer with major political connections and only minimal experience. Even though Mantua is a neighborhood of small rowhouses and narrow streets, the developer's plan called for plopping down a classic, highway-style retail cluster in the middle of those residences. Had the city bothered to do any market research, it would have quickly realized the location was all wrong for such an auto-intensive project.