First and foremost, a language must satisfy some need that is not met adequately by another existing language. Otherwise it's useless.
There are languages already with fast compilers, and some of them are pretty fast and have pretty good semantics.
Rust is really trying to offer a combination of things not available elsewhere: safety, speed, and control. But that innovation is based heavily on compiler features, which have a compile-time performance penalty.
Assuming rust succeeds on delivering an innovative new language, they can secondarily try to improve compiler performance. Or find ways to avoid paying some compile-time costs in certain situations.
First and foremost, a language must satisfy some need that is not met adequately by another existing language. Otherwise it's useless.
There are languages already with fast compilers, and some of them are pretty fast and have pretty good semantics.
Rust is really trying to offer a combination of things not available elsewhere: safety, speed, and control. But that innovation is based heavily on compiler features, which have a compile-time performance penalty.
Assuming rust succeeds on delivering an innovative new language, they can secondarily try to improve compiler performance. Or find ways to avoid paying some compile-time costs in certain situations.