I think the Rust compiler should write as its final log message "Resulting binary contains x bytes of unsafe code" (or something similar). That way, people are constantly reminded that their code depends on unsafe code, and they can try to reduce that with visible results.
Given the "unsafe guts" most of Rust stdlib contains, there's going to be some baseline of unsafe code that every project has. I could thus see this confusing new authors and users - you could have a project with zero unsafe lines that will still report a relatively large unsafe surface.
Besides, perhaps this would reinforce the notion that unsafe is - by its very nature - a bad thing. To quote Klabnik:
> it turns out actix-web is using a lot of unsafe code. That’s not inherently a problem. The problem is, a lot of that unsafe code is not actually needed.
If the code were actually needed, then there's no benefit in printing this metric - it just makes a project that is using the feature perfectly correctly look bad.
