The thing about coders is that they're often creators at heart.
The stated reason is likely only the excuse they told themselves to justify the project. But the real reason was likely that they wanted to create something, and this was a good justification.
Might just be me projecting though, because I do that all the time
I've stopped lying to myself, I'm making cool stuff just for the sake of it. It's like playing a video game, it doesn't have to be productive if I enjoy it.
The stated reason is likely only the excuse they told themselves to justify the project. But the real reason was likely that they wanted to create something, and this was a good justification.
Might just be me projecting though, because I do that all the time