The sketch is not the end goal. The end goal of the drawing process is what you learn while sketching.
I'm slowly getting back into the groove of reading blogs and updating this site after some time off to enjoy the first month with our new baby. I found 52 weeks' recent post about sketching, and loved the encouraging reminder for UX designers. I'll quote, because Joshua Brewer says it so well.
[D]on’t worry if you can’t sketch. In fact, if you’re too good you might just fool yourself into thinking your sketch is a deliverable. It’s not. The real value of sketching is that it allows you to explore and refine ideas in a quick, iterative and visual manner with little overhead or learning curve. Rapid ideation around flow and interaction, layout and hierarchy, can be quickly established, rearranged or discarded wholesale—all without ever touching a computer.
I like the reminder that sketching is thinking. For me, it is the thought process, decision making, and learning, not the quality of the product in this activity that makes sketching an important part of the design process. For me it even continues from sketch to wireframe. The lines blur when you can discard and start over easily and repeatedly in whatever medium.