I wonder though if there is a reluctance to adopt an approach similar to King's because people are wary (possibly subconsciously) of killing their enjoyment of the process: 'Don't turn your hobby into a job' is advice that you hear a lot.
Perhaps those who are prolific have their eyes more on the end result (a good book in 3 months) rather than the act of writing and that helps them deal with this as well as being more generally motivating to produce good work.
