A real poet or writer may not use everything (s)he writes for months but they still write (bad first drafts or just work that they'll never use). Also, for a real poet or writer, that is their job. So they HAVE to write, even if they miss a day or two. For someone who writes for hobby and wants to get good at it, it helps to have a plan like this in place. Hitler would have been an artist if he had the self-discipline to create something - anything- everyday.

If writing/exercising/insert-any-habit-here works for you by doing inconsistently, good for you. It works for the OP when he does it consistently. To each his own.