In your case, I would say that it is not merely of some importance, but is of fundamental importance, that you not only be organized, but that you manifestly and undoubtedly be seen to be organized. (allusion to a quote in http://en.wikipedia.org/wiki/R_v_Sus...parte_McCarthy )
I would suggest therefore that you expend some effort in attempting to understand as clearly and fully as possible what exactly the committee meant by "organized", how they were able to perceive your degree of organization, and what impact it has or is seen to have on the university, students, members of the committee etc.
You might want to consult an objective observer -- possibly another professor whom you trust -- to help interpret the committee's message and figure out what they meant. You might also want to review the actual wording of the committee's comments at regular intervals. That way, you may be better able to direct your efforts in the most fruitful directions. For example, possibly the committee's only real concern is that you submit marks on time; or possibly their concern is something else, or some combination of things. "Organized" can mean different things to different people.
You might want to define a goal, area of focus or other higher horizon of focus something like "become organized to the committee's satisfaction". This way, you can try not only to satisfy your own, or David Allen's, or this forum's definition of organized, but you can focus on satisfying the committee's idea of what organized is, and to do it in such a way that it has a positive impact on the university and is perceived by the committee members.
Inability is an abstract thing involving comparison with alternate universes; it cannot be experienced.