With dynamic languages (certainly Python, Ruby, and JS), there's a definite lack of nudge from the tooling to translate from "interchange" format into an intern

With dynamic languages (certainly Python, Ruby, and JS), there's a definite lack of nudge from the tooling to translate from "interchange" format into an internal "smart" format (procedural code + everything is a hash = easy hacks). Whereas with something like Scala, the tools make it very clear that if you serialize/deserialize on the periphery, you're in for a bag of hurt (or, at the very least, fighting with one hand tied behind your back). This is not to say that one tool is better than the others, but tools do have opinions, and while being more permissive/ambivalent makes throwing together a quick script easier, a tool that nudges you in the direction of building something in a more-sustainable way is useful when building nontrivial systems.