I don't doodle nearly as much as I should. I think it's fun. And cartoonist Pete Emslie backs me up on this.
I especially like to doodle because I feel I can draw completely in my own natural style, as loose, spontaneous and free of the constraints I might place on myself when drawing for a paid commission, particularly when the client is expecting something to look a certain way. When one doodles, there is the distinct pleasure of knowing that you are doing it just for yourself, not subject to anybody else's approval nor what they would be willing to pay for it. No, you yourself are the only one to satisfy and, heck, even if you don't like it, you haven't invested much time or effort in creating it. If it's good, maybe you'll file it away for future reference, and if not, it joins the rest of the newspaper in the aforementioned recycling bin.