Unfortunately, writing programs isn't an occupation for old people.
EDIT: To be more precise, I cannot image that I will write a program after my retirement. To me, writing ephemeral programs is the opposite of the artful activities described in the article.
Programming can be gruntwork. Programming can be highly disciplined engineering. Programming can be math. Programming can be artistic expression.
The beauty and curse of working with bits is that they're as flexible as you want them to be.
Programming satisfies part of my desire for artistic expression. I don't plan on quitting until I'm dead - I'm more passionate about computing, from high level abstractions and algorithms down to individual lines of code, at 39 than I was at 19 or 29. And I know a lot of people older than I who are way better than I am, and just as gung-ho as they were 20 or 30 years ago.
I don't think it's true, but I believe the programs your write for leisure and those you may have to write for work may be quite different. In fact, in some line of software work you rarely have to write whole programs.
EDIT: To be more precise, I cannot image that I will write a program after my retirement. To me, writing ephemeral programs is the opposite of the artful activities described in the article.