We make schedules for many reasons, but not out of some deep motivation, need or reason. This is why so many self-created schedules can be frustrating because we think they’re important but don’t care about them. I’m all for scheduling, but not a schedule as self-abuse.
With regard to my own work schedule, I try to get a book finished about once every 12-18 months. The main reason for this is simple: life's short, and even as finicky as I am with ideas, I suspect I have a great many different kinds of stories to tell before I crumble to dust.
I hate that I feel like a loser if I can't adhere strictly to this schedule. But it happens, and for many perfectly good reasons. My day job keeps me from starving, and even though I can carve out time for writing, I can only carve out so much. Plus, I have a real life outside of all that, and responsibilities that go with such a life.
From time to time I wonder how much more I'd write if I had no day job except writing fiction, and then I remember a) I can't make a living doing that (damn few people can), b) the living I'd make would be vastly inferior to the one I have now, c) the kind of writing I'd probably have to do to make such a living would render the whole exercise hardly worth the trouble, and d) even if I could make the equivalent of the living I have now, I wouldn't want to disconnect myself from daily life lest my work become increasingly insular.
Some healthy tension is needed between keeping the wheel of production turning and leaning on myself for being a lazy slob. When a couple of days go by and I don't do anything I can charitably excuse as "writing", I do feel wretched. I also know full well that's just me talking, and that I cannot turn that into a bludgeon to club someone else with. Everyone's schedule must be their own damn business.
One other thing Steve mentions in the above link is how schedules provide us with a sense of control. The great secret of life is that control is an illusion; you can't really control anything except your own immediate responses to things in the moment, and even that takes tons of work. I like thinking that just because I say to myself "I'm going to finish this thing by Christmas" it will, in fact, happen that way, much as someone might tell themselves they can't possibly be bankrupt because they still have blank checks in their checkbook. One day I'm going to be wrong about such a schedule — in fact, I already have been, many times — but I also know without the motivation only I can give myself, I won't get much of anywhere at all.
Am I competing with other authors in terms of a schedule? I never saw it that way. The only one I ever felt I was in competition with was the part of me that says this isn't really worth it. Then I think about that woman who read one of my books and later told me that book was one of the reasons she didn't throw her life away, and I gently remind myself that part of me doesn't know what it's talking about. Where my schedule feels like competition, it is only the kind of competition Tennessee Williams also saw: “Time is short and it doesn't return again. It is slipping away while I write this and while you read it, and the monosyllable of the clock is Loss, Loss, Loss, unless you devote your heart to its opposition.”