Go will never be nearly as ubiquitous as C. It's plug-ins API is terrible. Rust users definitely don't want a GC language to replace 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.
Regarding plugins, yes that is the package I am referring to. The idea of dynamic loading is completely ignored in the Go programming language but it is used in many, many other languages (i.e. Java, Python, Lua). Go's support for this feature is lacking and should be fixed for it to interact with other languages.