It's a weird system. A dissertation isn't really a publication, not the way an article in a peer-reviewed journal is. It is a unique document in one's academic writing career, high-value for what it represents (an advanced degree) but low-value in terms of your publication record. Dissertations are considered "gray literature," and are rarely read or referenced.
In the academic ideal, all the material in your dissertation will be published elsewhere, usually as multiple papers, polished, condensed, perhaps with a few extra analyses thrown in. It's understood that this tranformation takes time--often you're well into your first or second post-doc before you finish publishing your dissertation work. But this is what makes the work "real." Your degree is not contingent on publication--many PhDs have never published their dissertations--but your academic reputation is.
This leaves someone like me, who isn't pursuing a career in academia, in an interesting situation. I had a conversation with my advisor yesterday about publishing, which prompted me to consider in some detail exactly what my motivation is (and isn't).
ITEM: Publication is an integral part of the scientific endeavor and advances the state of human knowledge. I believe this, but I also believe that my written thesis already satisfies this particular aim. It contains all the information that would be in published papers, and while theses were once difficult to obtain, that just isn't a problem anymore in the Searchable Electronic Age.
ITEM: Publication means you get practice writing. My advisor mentioned this in our conversation yesterday, and it's not false. But this practice is a drop in the bucket compared to my two blogs, private journal, extensive personal correspondence, fiction and poetry. And frankly, all these other writing pursuits are far more interesting and useful to me than writing academic papers.
ITEM: Publication means a job and therefore a paycheck. (This is at the other end of the spectrum from the noble aim of advancing science.) Academics don't get paid per paper, but the number and quality of publications weigh heavily on hiring and salary decisions. However, I am no longer being paid to be an academic, and therefore publishing academic papers is not a job, it's a hobby. In fact, it takes time away from other hobbies I enjoy more.
ITEM: Publication builds your academic credentials. Rather entwined with the question of money is the question of reputation, and quite simply, in academia, the more papers the better. It doesn't matter if you're a tenured professor, people still want to know how much you're publishing, and judge you accordingly. For me, of course, this is just as moot as the previous item. Placing more academic
papers on my CV accomplishes little for me professionally.
ITEM: Publication is an act of goodwill toward your co-authors. This is a very important point to me. No dissertation is completed in a vacuum, and my research involved a large number of collaborators for whom I have tremendous gratitude and respect. Publishing papers with these people as co-authors is an act of service, a way of demonstrating respect by showing that I value the work we did together. And on a practical level, it places more publications on the CVs of these co-authors, with all the benefits that entails for them.
So. My exclusive motivaton to publish is apparently respect for my collaborators.