If you talk to the coders that participate in that section you'll find that their motivation is really about the enjoyment of programming. But part of the enjoyment is also related to knowing that you are making something that someone needs and appreciates.
That's why it's so satisfying and reinvigorating to read blog entries like this one..
How I Got Someone to Make This For Me, or Why DonationCoder.com Is Pretty Awesome: ... I posted my issue on the DonationCoder forum, and very quickly received a response. A word about these guys: they know their software pretty well. Several talented and patient developers frequent the forum and are often ready with helpful advice or a solution for clearly-stated issues. Some of these guys have created literally hundreds of ‚ÄúCoding Snacks,‚ÄĚ whose use cases range from the basic to the utterly arcane. In all cases, someone just like me piped up with a small, unique problem that had no prior solution, and someone stepped forward to help out. In my case, developer Skwire came to the rescue. Within a few forum posts, I had the software I needed..