>but I believe fragmenting the community has almost always led to the overall downfall of a language

Warning, I am not a professional developer, only a mere scripter.

Aren't forks and transpiled languages sometimes a driving force? Typescript/coffeescript pushed changes in Javascript. Scala on the VM pushed changes in Java. jQuery as a DSL of javascript even pushed changes in the language.

And in all of these cases, the branch language/framework eventually becomes less relevant, but that does not take away the utility and influence they provided in their time.

So if someone imagines running a Golang fork and successfully develops the fork with new features and/or better processes and faster iteration, it may be useful even if they end up dying once and if Golang itself incorporates the changes.