I much enjoyed the viewpoint and presentation. Thanks.
Have I written documentation "for free"? Yes. I often write documentation for work, on my own time and initiative. I consider that "free".
I enjoy participating in the NAGW, nagw.org, google group. I often prepare posts on "my own time".
Why do it for nothing? Because I think documentation for work is the "right thing to do". Especially if you are the responsible doer.
If it is not for work, because it helps me incrementally.
The writing helps two situations - a chain of failed attempts due to memory loss, and a chain of repeated unsuccessful requests for assistance due to inadequate problem statements.
So since I like doing, and I don't get paid for being creative, writing documentation is useful to me in my "free time". I believe if helps me to move forward. Like a trail of breadcrumbs.
Oddly, the last two days I was reviewing some year-old scripts I wrote for myself. And the pods. Tried to see them through Perl Best Practices, 'Ch. 7 Documentation'. Remember the opening quote?
"Documentation is like sex: when it's good, it's very, very good; and when it's bad, it's still better than nothing." - Dick Brandon
PS. I don't consider myself creative, even though I prefer to make my own chili. I like the doing.