Unfortunately, the kinds of people who care about that sort of thing overlap heavily with rust's intended user base.

Also, end users might not care that much about binary size, but distribution maintainers do -- they want to fit as much functionality they can within a reasonable-sized iso download. If including a rust program in the base OS means omitting a dozen C programs that would have fit in the same space, that's a hard sell.

I am optimistic that these kinds of issues will be worked out as the language stabilizes and the tools improve.