>  If interfacing with a driver is so hard, how will interfacing with
  > hardware be easier?

It really depends. The key is to identify the proper ways to make the abstraction as safe as possible. This is a fairly new skill, in a new language. Said post was good, and the author has been using Rust for a long time, but one person failing to do so doesn't mean that it's impossible.

I'm still a noob at this kind of thing myself, but I recently wrote a (tiny) driver for a memory-mapped device. My first iteration had tons of unsafe code. My second iteration had three lines of unsafe code. My latest iteration has zero unsafe code, though you do need one call to an unsafe function outside of it in order to construct it. (to create a slice from the raw memory location that's mapped.)

That is, of course, pretty much the simplest possible case. But I believe the pattern will hold, over time, as people learn how to do it.

  > Even rust can't take those thrones away from C.

Rust is faster than C on some microbenchmarks. We'll see what the future holds.