On Discipline

I have been hearing recently about people who write (or wrote) as a discipline. Apparently Jon Foreman, one of my favourite song writers, makes it his discipline to write a song every day. Some of them may be horrible, and it is likely that no more than a handful will ever be heard, but how much more will you develop writing that often. It greatly increases the odds of greatness. Also, in my novel class, the teacher told us about a novelist who would write a novel in eleven days and was one of the most prolific novelists ever. Sure, some of the novels were less than great, but just to write that much that quickly is remarkable.
What if I wrote poetry on a daily basis? Yeah, I would probably write a lot of less than fantastic poetry, but I have always dreamed of being a prolific writer, and I think it would sharpen my technique a great deal. I am thinking of beginning this discipline, but I worry about it making my writing more shallow. However, if I am not shallow, I suppose my writing would not necessarily become so. It would probably get me to write shorter poems as well, something I do very rarely.
Why not? I'm a writer aren't I? I will not be posting all of these poems. Needless to say, not all of them will be that good, and I need to come to terms with that before I begin because I have a hard time accepting less than excellence. When one of them is good, however, it will probably be found here.