[eximius]

Anecdotally, it is named after a certain multi-stage lifecycled fungus. Much better :)

[SilasX]

Maybe so, but if they had named it "filth" and explained that it was this Uber-geeky reference, I'd still say it's a bad name for the same reason.

[eximius]

I also tend to think of thermite before uncleanliness when I hear rust. Rust is just iron oxide, not anything dirty.

[SilasX]

When I hear "rust", I get images of rusty pipes, old rusty nails, faucets where the water is tainted with rust, and people's skills getting rusty. I feel disgust, and it's why I didn't feel particularly eager pursuing it further.

[steveklabnik]

That's one of the various reasons for the name; there's no single reason Rust is named "Rust."