It's less of a problem, I think, than you think it is. In the enterprise world, Java is / was a similar de-facto standard because they paid good money for Java enterprise servers, Oracle databases, trainings, frameworks, the works.
I'd rather work for a monoculture than a cowboy pick-whatever-you-want one; it's not a dichotomy, sure, but I'm aware of the latter for business continuity. You run into scaling and talent acquisition issues. Bus factor. Etc. If you as a company can say "We need a Deno developer" instead of "We need a full-stack Javascript/NodeJS/Scala/Java/Go/Rust/Erlang developer" (just to name a random array of languages) you can hire and train a lot better.
I'd rather work for a monoculture than a cowboy pick-whatever-you-want one; it's not a dichotomy, sure, but I'm aware of the latter for business continuity. You run into scaling and talent acquisition issues. Bus factor. Etc. If you as a company can say "We need a Deno developer" instead of "We need a full-stack Javascript/NodeJS/Scala/Java/Go/Rust/Erlang developer" (just to name a random array of languages) you can hire and train a lot better.