e.g.: Using python, I can do games, scientific/bio work, math, web backends etc. The same time investment in GDScript will only net me experience with GDScript which right now only exists in Godot.
But suggest a different language or a DSL for something, no matter how much sense it makes (sometimes getting simple SQL in places is a political struggle, and it's unfortunate when teams develop a "regex expert" even though all the regexes are simple), even one that is already super similar to one they already know like GDScript and so is rather trivial to learn (no one's asking you to learn something on the order of complexity and different-to-others like Haskell here), and devs start putting their foot down and saying "Of all the things, I"m not learning that!"