banner ones, lettered intellectuals,rafters meaning in this context??

Very few veteran critics tend to be enamored of the recent decade in cinema. Nonetheless, based on movie reviews many could easily come to the conclusion that the last ten years were indeed banner ones. Once the province of lettered intellectuals, a few even household names the role of the movie critic has been filled with by those lacking any notable credentials. With this flood of veritable tyros opining from the rafters, a movie’s overall rating—as compiled and tabulated by popular Internet sites–often times confers a patina
of respectability on a film, an assessment that posterity will most likely deem specious.