It's a cherry picked, out-of-date counter-example. Swift isn't designed for building drivers.
In reality, a lot of Swift apps are delegating to C code. My own app (in development) does a lot of processing, almost none of which happens in Swift, despite the fact I spend the vast majority of my time writing Swift.
Swift an excellent C glue language, which Java isn't. This is why Swift will probably become an excellent game language eventually.
