While I enjoy putting on my viking hat and woolly sweater, getting out the skyr an playing some Sykur while I’m studying Icelandic– Icelandic would still be Icelandic without all of that cultural stuff. For every charismatic word that says something about the way of life on a rainy island, there are a hundred words that could be describing anything, anywhere, in any culture. Culture does shape language, but it’s fingerprints are shallow, easy to miss, easy to ignore.*
Whats wrong with thinking that culture and language are synonymous?
If are a Tolkienist and are writing entertaining ficitonal anthropological reports, then this isn’t a problem at all.
Where this becomes a problem is all the other application of conlangs.
research languages. mini-fake languages have been used in experimental linguistics. And the researchers did not need to start with a description of the fake people that used the fake language. It would make their research look ridiculous.
lingua franca usage -i.e. auxlang. I don’t need to elaborate on how much breath and ink has been spent griping about if one auxlang favors one culture over another.
augmenting languages – i.e. sign language and other communication systems for the disabled. The medical community is not involved in the propagation of fiction, nor cultural imperialism.
Fans have a culture. They are living it right now. You don’t need to provide them with one, unless that is what you enjoy doing, in which case, hey follow your joy.
There is more to life than just Tolkienism.
*[On the topic of Icelandic, I'd go so far to say that the topmost defining thing about Icelandic culture is their language. Their culture is often borrowed-- the style of food mostly comes from Denmark, technology is mostly imported, especially now that they've moved off the farm. If language and culture are the same thing, then Icelandic should have disappeared as soon as life styles changed and Icelanders would have found themselves speaking Danish on account of adopting a few Danish customs. But that is absurd! Most of the time a language exists as a communication system independent of all the things anthropologists study]