But what does it say about a person if they don't? Not necessarily the opposite. In my case, programming is a passion. I've been doing it for fun since I was about five years old. I've been lucky that I could take something I enjoy and turn it into a career, but the day job and the programming I do at home are very different things. My day job is about deadlines, requirements, standardized platforms and change control. They're about the mechanics of delivering products as much as they are about the creativity of writing software. So it's nice to come home and spend some of my increasingly rare free time (I have a wife and a three-year-old) just experimenting and learning.
There's nothing really wrong with that, but there's always room for growth, and I see benefits to myself in 'putting myself out there'. I've recently embarked on a couple of longer-term personal projects. One of them is yielding a Werkzeug-based web app framework as an artifact, and I do intend to release that as open source eventually, even though for the moment it's easier for me to keep it in sync by developing it in the app's private repository.
All of this led me to conceive of the following analogy. Don't think about it too much, though, or it will fall apart.
Some programmers are like rock stars. They create a lot of content that they release with their own name attached to it, and it's a name people in the community know well. Their notability comes with exposure to direct criticism, and popular opinion of them can bias the reception of their work.
Other programmers are more like session musicians. You've probably never heard of them, but they've contributed professionally to many projects. You might even have unknowingly experienced their work as part of a larger product.