I generally agree with you, having had to debug nasty Clojure code because somebody thought it was the best fit for the problem (it actually was) but then left the company.
I think prescribing languages should be somewhere it between - settle on one RAD tool/dynamic language (Ruby/Python) for quick new projects, one performant language (Go/Java/Rust) for core services, and one UI framework (React/Angular/Vue).
It is important to use the right tool for the right project, but from a selected set of options that the company has built workforce competency around. Using the latest and greatest often gives you the best technical solution but often at the cost of maintainability and predictability.
I think prescribing languages should be somewhere it between - settle on one RAD tool/dynamic language (Ruby/Python) for quick new projects, one performant language (Go/Java/Rust) for core services, and one UI framework (React/Angular/Vue).
It is important to use the right tool for the right project, but from a selected set of options that the company has built workforce competency around. Using the latest and greatest often gives you the best technical solution but often at the cost of maintainability and predictability.