I find it odd that nobody sees the elephant in the room: productivity is determined by the "fit" between a developer's or team's mindset and the language! None

I find it odd that nobody sees the elephant in the room: productivity is determined by the "fit" between a developer's or team's mindset and the language! None of them matter in isolation. If you have a team of people who likes to think dynamic, functionally and meta-linguistically, just pick the best Lisp-family language for your needs. For another team who prefers to think dynamic, functionally, with actors and pattern-matching, pick Erlang or Elixir. Someone who likes to think pragmatically, likes obviousness and simple static typing should probably pick Go if he's also "minimalistic" or Java otherwise. For a "move fast and break things + fuck this functional programming bullshit" thinking team, pick the best version of PHP (Hack & HHVM) etc. Want "move fast and break things + ok with event-driven + some sprinkle of functional programming goodness", then use Nodejs. For example, for "move fast and break shit" prototype development I pick Nodejs over PHP because my mind "works functionally" and every attempt at writing functional code in PHP is pure pain. There is a reason why there are so many languages: people think very very very differently from one another, but at the same time they think similarly enough that they can gather in "tribes" around certain technologies and idea!