Here’s an interesting read from Mental Floss about early rejections for bestselling writers. Anyone who can finish this sentence — “Dear Author: Due to the volume of submissions we receive, we are unable to . . . “ – understands that same frustration.
And a related article at PW about unfinished or unpublished manuscripts from bestsellers. The only one on that list I’ve read is Billy Budd; I can see why it wasn’t published during Melville’s lifetime.