"Bartleby the Scrivener" is one of Melville's more challenging short fictions and your question requires an answer that is more oblique than usual. To me, Bartleby the Scrivener has always represented passive resistance...to anything besides his one set routine. With his answers of "I prefer not to" he "closes" himself off to his employer and from the other employees in the office. The spatial setting of the office (him being so confined when he works), might also be testament to this.
There are others who believe the lawyer reciting the tale is nothing more than a collector and he's collected various lawyers and personalities in his place of work. This might answer why Bartleby is so confined when he works and even when he works diligently he is "closed off from everyone in the office"-he's on display perhaps and this is the collector's niche/shelf/display case for him. The lawyer seems the collector since there are "ground-glass folding doors divided my premises into two parts, one of which was occupied by MY scriveners, the other by myself" (744). This is a collector's case if any.
(Concise Anthology of American Literature, Fourth Edition)