I needed a static site generator, and a random program to teach myself Go, and hade a spare domain laying around.
No, really, that's the whole story.
So why not use and existing static site generator?
How would that teach me Go in any way?
I mean, I could probably pick up one of the existing static site generators written in Go, but it would be months before I could make any meaningful contributions, which negates half the purpose. I'd basically be left looking for a project to learn Go basics so that I could eventually do the thing I originally set out to do. I'm silly, but I'm not that silly!