I don't get this. It is like being an accomplished painter, but never painting anything for yourself. Or a carpenter, and not making your own table or chairs. As a coder, you have the ability to create almost anything. How can that knowledge not tempt you to create something yourself?
I'm not sure I would take "only" in that case too literally. There are a lot of people who genuinely do enjoy programming but get quite enough of it at work, thank you very much. In my case I do a lot of writing (words) for work and like doing it--among other things that are part of my job. That doesn't mean I spend every night working on writing the great American novel--though I do know writers at work who also do…
To add to this, it’s not only unhealthy but leads one away from the concrete reality we live in and this results to out of touch thinking.