I object to the idea that the cultures of Treklit are shallow, however. If anything, I find the different Treklit cultures to be quite deep, and quite a bit deeper than what the canon often featured.
I wasn't clear: I think that was a more general point about the franchise in general. You are right, the lit has done at different points much to deepen certain groups: in the 80s under certain authors, and since the commencement of the relaunches last decade. I wouldn't deny that: from Andorians to Cardassians to Klingons to Romulans to Tholians to now Breen, Tzenkethi and others, they have become distinct: more than bumpy foreheards or coloured humans.
I used 'shallow' only in the sense that there is (dependent on the author) little to suggest a great depth of culture, history and emotion behind each race in general, only little touches and little senses. Each race doesn't have a unique way of talking, in general, nor a unique way of referecning history, nor a canon of culture. Nothing suggests their alien (from one another) ways of perceiving and thinking. Nor does much suggest the cosmopolitan nature of the Federation, the two main empires, and other worlds. Each race also doesn't quite have the suggestion of the variety that humans are depicted with, except usually through the relatively simple presentation of dualistic political ideology (such as the Andorians in
PoD, the Romulans over the past decade, or the Cardassians after the war). This still leads to the sense of monoform cultures, with the Federation (most of all) an Anglo-American (mainly the latter) hegemony with occasional, rather anglophone contemporary western-cultured, member aliens. They encounter rather anglophone, contemporary-western-cultured aliens and empires. It doesn't matter that the President is based in Paris, there is nothing French about the political system of the Federation. It's rather similar to the rather English Jean-Luc Picard (although thank you authors for making him more French!). Does this make sense?
Anyway, as I stressed before, this is not an attack on Treklit, which I find really rewarding - most espeically those books which go to such lengths to build 'worlds', even if drawn from normal western tropes. So books like
The Never-Ending Sacrifice, many of the Typhon books, the DS9 relaunch books, the works of various authors, even the 'viking'-esque Left Hand of Destiny books and the eponymous head-throwing books of this thread: I really appreciate the attempts to continually do more with the ip.
And as you say Sci the TV shows set the frame. But consider how revolutionary the literature has been concerning the de- or reconstruction of TV trek's frames: be it the dark militarism only suggested in TOS and its movies taken to a massive, logical and very deadly highpoint in Vanguard, or the sexual habits of many characters, or the actions of certain characters, such as Sisko, that
can be extrapolated from the show, but which are wonderfully darker or more dramatic than the show would ever go. These show that the lit can escape the ... less ambitious or sometimes rather dull conceptual ... confines of the show, and surely extensively introducing language differences, senses of dialect and senses of history/culture through idiomatic difference are potential ways to subtly and rather literarily develop on the relatively monoform, American, presentation of television?