[dragonwriter]

Every maintained project is a continuous Ship of Theseus rewrite, but yes, if there's a language your team is more productive at writing correct code in and that provides better performance, there's an easy choice to make. That's very often not the case, though, and as well as team it's often project scale dependent, and projects often start at a scale where the calculus is very different from where it might be years down the road.