Maybe "stable" was the wrong word. Perhaps "proven stable" would be better. It's not that "new and shiny" can't be stable, it's just that it hasn't proven itself stable yet. It hasn't been around long enough to prove it. So it's more using technology that has over a decade of proven dependability, over something that may or may not be.
Elixir, Clojure and Scala cut across this distinction. They're very new and shiny but built on proven technology. In that sense maybe they're a better bet as they definitely bring something new to the table and help solve hard problems. I think Clojure suffers most from this familiarity bias as I'd argue it's at the top of the excellence tree despite being largely ignored by an industry forever wedded to C# and Java.
