I actually think that design looks really good - don't forget, people that read HackerNews may be more inclined to see these sorts of themes around (as they're usually used by people just launching a product to see if there's any interest). Most users might not see the same theme that often, if at all.
I think the Hacker News people are probably the target audience for BugMuncher. But in any case, the design is fine. I'm actually impressed it was only $20.
Having said that, I've had a lot of compliments on the theme, and for $20, I've got no complaints :)