Ha ha, good point. I agree, seen it happen more than once. Some people don't feel comfortable with anyone who is in some way different, even regarding likes about (often trivial) things such as tastes in food or music or sports, etc. Insecurity, I call it. Linus (of Charlie Brown / Peanuts comic fame, not Linux) and his security blanket come to mind. Images:
https://www.google.co.in/search?q=charlie+brown+linus+charac...
This is a highly valuable work skill for a technical worker if he/she has the need to work with clients, present updates or discuss requirements, much more than having a few small GitHub repos. By focusing in side projects you can be filtering out these skills in your workforce.
Possibly the author is better off this position.
This is becoming more and more important as science/technology keeps getting compartmentalized. Not to go as far as the medical doctor who rediscovered numerical integration [1], but I have the certainty that in my research I'm doing many things in a horribly inefficient way, out of ignorance. Just the other day I learned about k-d trees and sped up a piece of software in my lab by an order of magnitude...
To that end, I quite like writing documentation, especially after finishing a large milestone. It's a good break from just coding, while also being very helpful for the team as a whole.
For instance the fact that you write novels for fun suggests me you would be able to write good, long documentation or manuals if required. I've known good programmers absolutely incapable of communicating their ideas in writing to other human beings.
Some, when told that they needed to prepare a detailed, well written technical report on the software they are building for a client, looked like if they had received a death sentence.