I didn't say it will, nor did OP say that he wanted the alternative to be as ubiquitous as C.
When you refer to Go plug-ins API, do you mean this[1]? Because I wrote a fair amount of Go and wasn't even aware of this package. And while I don't know whether it is terrible or not, I'm pretty sure this package in particular is not relevant for most Go applications. So maybe you meant something else?
I didn't say Rust users want a GC language to replace C, I don't know where this is coming from.