Fun story about the history of that paper:
We used to think Rust needed a runtime to be safe, so it had one. There was an attribute, #[no_std], which would not link in the runtime, and also get rid of the standard library. As such, the decision was made for std that it should just panic on OOM, because you'd be clearly writing an application, and generally, you don't even seen OOM in that use-case.
Fast forward a few years, and we remove the runtime, and suddenly, it's not impossible to use std to build things like operating systems. So now, people use it this way, and see that it might not be well-suited to that purpose.
So in some ways, the claims put forth by that paper are historical accidents. Which doesn't mean that they're not interesting, or valid, it's just that an additional possibility came up, which challenged a design assumption.
We absolutely do care about the lowest-level case with Rust, and had a number of discussions at the workweek (Mozilla all-hands, full week of meetings) to talk about how to improve the "I'm writing a kernel" case with Rust.