We don't procrastinate for complex reasons; everything boils down to a thought that you're avoiding.
Sometimes -- rarely -- the thought you're avoiding is about the task itself. But when it's chronic, the thought is nearly always something about you, and what it "means" about you if you don't do it.
I actually wrote part of another article about procrastination, before this one, following a theory much closer to yours. I ended up determining that it wasn't going anywhere, but I think what I do have clarifies your theory immensely. So at the risk of putting words into your mouth, here it is:
In the 1950s, B.F. Skinner conducted a series of experiments which established the principle of Operant Conditioning. The canonical example of this sort of experiment is a rat in a box, which receives either a reward (food pellet) or a punishment (electric shock) when it presses a button. There is a lot of research on the effect of varying the conditions - species, target behavior, feedback type and schedule, etc - but in general, behaviors that produce rewards are promoted, and behaviors that produce punishment are inhibited.
Now, suppose an experimenter hooked you up to a mind-reading machine for a week, and every time you thought about elephants, he came and gave you $20, up to some rate limit. You would quickly become obsessed with elephants, and years later you'd still be patronizing the zoo. Reinforcement, it would seem, works for thoughts much like it does for behaviors. Now consider the opposite experiment, where every time you think about elephants, you receive negative feedback. This experiment can't be done with electric shocks (at least, not ethically), but it has been done. The Game is a mind game which some people play, with one rule: if you think of The Game, you have lost, and must annouce it to those around you. Insofar as operant conditioning applies to humans, and thought is a behavior, and embarrassment is punishment, The Game should be very easy: it conditions players to stop thinking about it. In fact, the opposite is true: players of The Game end up in a spiral where they can't think of anything else.
Clearly, the theory of operant conditioning does not apply straightforwardly to thoughts, and we shouldn't expect it to. After all, if thinking about something causes a strong reaction, positive or negative, then it's probably important enough to think about more. However, we still need a mechanism for choosing topics to think about, which means that some things will reinforce a topic and others will inhibit it. Reward and punishment can't fill these roles.
Where I got stuck was on trying to figure out just what does condition us to think more or less on a topic, and I don't think that can be answered accurately without much better instruments and experiments than are currently possible. Clearly, when people enter procrastination spirals there is some sort of conditioning going on, but negative affect alone can't be the cause; The Game seems like a strong refutation to that.
Punishment presumably doesn't work for thoughts, because it rewards the negative of the thought in the same movement. I expect that it's rather switching to procrastination that is rewarded, not continuing on the task that's punished. The behavior here is not static "thinking a thought", but rather a transition between possible thoughts.
The longer you try to concentrate on the task, the more willpower you apply to it, the more rewarding the behavior of switching the attention to procrastination becomes. And so, you learn to do it automatically, thinking of nothing else whenever you start thinking of getting the work done.
I have a paper to write. Where do I start? The first time I asked this question, it was easy: just sit down and start typing. I wrote a few hundred words, then got stuck; I needed to think some more, so I took a break and did something else. Over the next few days, my thoughts on the subject settled, and I was ready to write again. So I sat down, and asked: What do I do next? Fortunately, my brain had a cached response ready to answer this question: Solitaire!
So I procrastinated, and every time I asked my brain what to write, I got back an answer like "Don't bother!". Now a deadline's approaching, and I still don't have much written, so I sit down to write again. This time, I'm determined: using my willpower, I will not allow myself to think about anything except for the paper and its topic. So I ask again: Where do I start? (Solitaire!) What thoughts come to mind? I should've started a week ago. Every time I think about this topic I get stuck. Maybe I shouldn't write this paper after all. These, too, are cached thoughts, generated during previous failed attempts to get started. These thoughts are much harder to clear, both because there are more of them, because of their emotional content, but I'm determined to do so anyways; I think through all the cached thoughts, return to the original question (Where do I start?), get my text editor open, start planning a section and... Ping! I have a new e-mail to read, I get distracted, and when I return half an hour later I have to clear those same cached thoughts again.
Many authors say to stop in the middle of a thought when you leave off, so that "Where do I start?" will always have an easy answer. This sounds like a solution, but it ignores the fact that you'll get stuck eventually, so that you have to stop, at a spot that won't be easy to come back to.
In order to stop procrastinating, there are two obstacles to overcome: A question to answer, and a cached answer to clear. The question is "What do I do first?" and the cached answer is "procrastinate more". Knowing that "procrastinate" was a cached answer makes it easier to get past, but the original question is still a problem. Why is deciding what to do first so often difficult?
When I'm programming, I make a long, unorded to-do list for each project, listing all of the features I plan to implement. When I finish one, I go back to the list to pick something to work on next. Sometimes, I can't decide; I just stare at the list for awhile, weighing the costs and benefits of each, until eventually something happens to distract me. Most of the items on that list are harmful options, which serve only to induce analysis paralysis. It's the same problem some people have ordering off restaurant menus, and the same solution works. Instead of considering a series of options and deciding for each whether it's good enough to settle on, choose one option as the current-best without considering it at all, and compare options against the current-best.
Usually, choosing where to start, or what to do next, requires generating options, not picking one off a menu. When choosing, say, the topic of the next chapter, it's easy to convince ourselves that we'll come up with the perfect answer, if only we think about it a little more. If we take the outside view, we can see that this is probably not the case; and if we let thinking about one decision crowd out everything else, and think about it long enough without reaching an answer, then eventually we will settle on Solitaire as the best choice. When deciding how much thought to apply, remember: The utility we get from thinking about a decision is the cost of deciding incorrectly times the probability that we'll change our mind from incorrect to correct, minus the probability that we'll change our mind from correct to incorrect; and the longer we have gone without changing our mind, the less likely we are to do so in the future.
Procrastination is not a single problem, at least two: cached thought, and analysis paralysis, working together to stop us from getting work done. If we miss the distinction, then any attempts to find solutions will be doomed to confusion and failure; we must recognize and address each underlying problem, separately.