It seems to me that people have trouble with being bored. So they need to fill their time being 'productive'. Instead of drawing fancy headers for 'Wednesday' or 'Spanish' you could also just doodle for the heck of it. No, no, no, you are not allowed to just draw for the sake of drawing, you must be working on your productivity.
That is all fine of course, but I think you'd be a lot happier just drawing for fun and being smart and efficient about handling your todos as many have stated here, through basic lists on any piece of paper.
Consider: drawing a fancy header as a way to clear other things out of your mind and start considering things like "just what the hell do I want and/or need to do today?".
Consider: unique headers and other doodles act as memory aids when you are flipping through old journals looking for a particular thing. "I'm pretty sure it was close to a drawing of a blue cat eating pie."
I won't argue that Western civilization doesn't have a huge problem with wanting to pack every moment full of "useful productivity" though. If one of these gives someone an excuse to get down to some serious doodling then I can't see that as bad.
It is easy to find arguments for anything in hindsight as you did and that doesn't make the 'method' anymore valid or generally useful to everyone and I didn't say it is a bad thing.
I find it a shame that apparently many of us have problems with doing things just for fun without feeling guilty about not being productive. You can do whatever you want with your time though and for any reason. I am not telling anyone what to do here ;)
That is all fine of course, but I think you'd be a lot happier just drawing for fun and being smart and efficient about handling your todos as many have stated here, through basic lists on any piece of paper.