Others have commented that security type safety can be important even in applications that are not externally facing, but thats even sort of besides the point.

Others have commented that security type safety can be important even in applications that are not externally facing, but thats even sort of besides the point. When people talk about 'safety' in Rust, often times they are talking about the predictability that you mention. Highly threaded code can seem to run perfectly for some time before obscure bugs pop up. Rust's abstractions around thread and memory safety can help in those situations.