An interesting viewpoint about listening to "unsuccessful" rather than famous writers for advice in Salon.
I think this article has a valid point but would caution readers to know the difference between writers who aren't "successful" and writers who haven't had any success at all: the know-it-alls in advice chat rooms who've never been published but know how everything works. Or the grammar enforcers who don't understand style.
So, rather than unsuccessful, I would say look to the yeoman writers, the people slogging away in the field every day. The people who are working hard but not (yet) raking it in.