It's just for fun, mainly, a stretch of the imagination and maybe a little bit of a roleplaying exercise. It's maybe for a little depth and "local flavor". And it's optional.
This is pretty much how all my languages work. Take Teliya Nevashi-- it has two varieties, Earth Nevashi and Ianea Nevashi, because it is a personal artlang I want to use to talk about my everyday life, and it also has a pre-industrial conculture on another world that goes with it. I am really bad at the conculture end, so that ends up being spotty and disjointed, and the language will eventually be filled with all sorts of things that don't fit that setting, but I like that it is there. Even when I try to NOT have a conculture associated with a language, it always ends up with one somewhere in the back of my mind anyway.
Anyway, since our contrivance is that these are people living among us and blending in, no matter what values and beliefs we assign them, the language should be otherwise completely compatible with normal life for most everyone.
