That's very true. The most we can hope for is that Rust and other languages, such as Go and Swift, continue to chip away at the market share of C and C++. It'll be a long process.
I'm not a "rewrite everything in Rust" booster; as much as I would like to, that won't realistically happen. Instead, I see Rust as another player in the "programming language Renaissance" that has been going on since the mid-2000s. C and C++ are losing their dominance and instead are becoming part of a broad ecosystem of languages. And that's great: the fact that we have so many choices in languages now has been a very good thing for productivity and security.
> Actually that was thing I was thinking while reading this PDF -- a lot of it can be boiled down to "C and C++ have network effects". Particularly C++.
I agree. That's why I think this paper overanalyzes the success of C and C++. They became dominant because of network effects: simple as that.