Are Authors Technological Poseurs?

Recently, the JRuby team has gone through the motions of getting a definitive JRuby book underway. We've talked through outlines, some some chapter assignments, and discussed the overall feel of a book and how it should progress. I believe one or two of us may have started writing. However the entire exercise has made one thing abundantly clear to me:

Good authors do not have time to be good developers.

Think of your favorite technical author, perhaps one of the more insightful, or the one who takes the most care in their authoring craft. Now tell me one serious, nontrivial contribution they've made in the form of real code. It's hard, isn't it?

Of course I don't intend to paint with too wide a brush. There are, without a doubt, good authors that manage to keep a balance between words and code. But I'm increasingly of the opinion that it's not practical or perhaps even possible to maintain a serious dedication to both writing and coding.

What brings me to this conclusion is the growing realization that working on a JRuby book would--for me--mean a good bit less time spent working on JRuby and related projects. I fully intend to make a large contribution to the eventual JRuby book, but JRuby as a passion has meant most of my waking hours are spent working on real, difficult problems (and in some cases, really difficult problems). It physically pains me to consider taking time away from that work.

And I do not believe it's from a lack of interest in writing. I have long wanted to write a book, and as most of my blog posts should attest, I love putting my thoughts and ideas into a written form. I enjoy crafting English prose almost as much as I enjoy crafting excellent code. But at the end of the day, I am still a coder, and that is where my heart lies. I suspect I am not alone.

When I decided to write this post, I tried to think of concrete examples. Though many came to mind, I could not think of a way to name names without seeming malicious or disrespectful. So I leave it as an exercise for the reader. Am I totally off base? Or is there a direct correlation between the quality and breadth of an author's work and a suspicious (or obvious) lack of real, concrete development?