Well all of the linker script is just two standard memory map files, one for the 2040 and one for the 2350, so really it suggests that this needed very little code to make this work. The 6.4% shell represents a shebang line, two comments, and a single `set -e` call, after all.
There's nothing about embedded development in Rust that would make it more reliant on linker scripts than any other language. Github's count is misleading here.