I'd like to respond by this and saying I'm porting a largeish codebase over to Rust for one purpose: I can embed it other languages, and I can into it from any language that exposes an FFI.
The goal is to move all business logic out of javascript on an nwjs desktop/crosswalk mobile app and move it to Rust. The interface would still be javascript, but the core logic (and crypto) would live in Rust. This gives me a portable core I can move between platforms, and in theory all that has to change is the UI (but not really, because in most cases the platforms run Javascript).
I don't think Go can be as easily embedded (because of its runtime) but perhaps I'm wrong.
I'm sure that Go would have performance characteristics closer to Rust than Python would, but I'm almost certain Rust would still edge out Go.
I'm getting to the point where I'm almost as productive in Rust as I would be in either other language, and that makes Rust a no-brainer for me.