To play devil's advocate, most systems programming can be done even with a garbage collector. Midori was a project to build an operating system on a variant of C#, and although the garbage collector did impose technical difficulties, it wasn't a dealbreaker. Go isn't usable everywhere Rust is, but it can in fact be used for many things that previously would have been considered "systems" niches (which is part of why there was a somewhat prevalent misconception in the early days of Rust that they were similar languages). Prominent D developers have defended D's garbage collector (even though it's technically optional). Bjarne Stroustrup, the creator of C++, used to express great confidence that C++ would one day have a garbage collector.

...but you're right, Rust and its rise in popularity (and, conversely, the C++ community's resistance to adopt anything with garbage collection) have definitely narrowed the common definition of "systems programming" to exclude anything with a "thick" runtime.