So which tool will you require to handle the multiple versions of your package? Gonuts? Rx? It doesn't work. While it may be possible to have multiple tools, they need an agreed upon metadata format and strategy for dealing with versions. If the tool I like to use doesn't know how to deal with the package you made, I just can't use it. It splits the ecosystem by tool.

I don't think blessing a package necessarily means including it in the Go tool. RubyGems existed for a long time before Ruby started shipping it, but the community became unified around a particular tool.