Klingon poses a much more visible threat; it has glamour and visual media
on its side, as well as being a difficult conlang to master. Its culture
is small but vibrant, and translations of "Hamlet" and "Gilgamesh" have
already appeared in book form. Lojbanic culture need not follow the fannish
model of development to find food for thought in such lavishly detailed
tomes as "The Klingon Way" and "Klingon for the Galactic Traveller".
[Take two; rephrased by nitcion.]
If it may be argued that different conlangs are in competition for the same audience of potential learners (which is not in itself a given), then
Klingon poses a much more visible threat to Lojban than do other conlangs, including Esperanto. Klingon has glamour and visual media
on its side (which Lojban does not, and will not), as well as being a conlang rather unlike English (which is also a selling point of Lojban), but not extremely difficult to master (which is not a selling point of Lojban.)
Its culture is small but vibrant, and translations of "Hamlet" and "Gilgamesh" have
already appeared in book form. (A prominent Lojbanist was involved in the former. ahem So was another.)
Though Lojbanic culture need not follow the fannish
model of language development, it should find food for thought in such lavishly detailed
tomes as "The Klingon Way" (a collection of fictional proverbs) and "Klingon for the Galactic Traveller" (a disquisition into much fictional Klingon culture and associated idioms)...
The two languages are complementary in a different way (than Lojban and Esperanto)-- Lojban is thought to be serious and scientific, Klingon frivolous and fantastical. But this disregards the amount of hard work that was necessary to give Klingon the usability it now possesses (for it was never intended as a real conlang, in the beginning), and also the unacknowledged amount of fantasy and frivolity in Lojban culture.
This seems not to discuss the relation between the two at all, just Klingon itself - and should go on the Klingon page. Rephrased
(You ought to hear Nick & Shoulson at Logfest. 25% of the discussion is dominated by Klingon topics. Never do I learn so much about that language than when I go to Logfest. --xod)
(.i seni'ibo .ianai ko zerfusysku mi fo lo flalu pajni .i ca'i ma mi ce lo pendo poi mi ze'u na viska na casnu lo kampu se cinri vau .ue — mi'e nitcion)
Lojban and Klingon are completely different in their design philosophies. The point of Klingon is to zealously stick to the canon created by Mark Okrand. The point of Lojban is (was. the language is baselined now.) to create a complete, interesting, logical language, whose design principles are not arbitrary. Perhaps this underlies nitcion's extreme hardlinerism. Then again maybe not. I suppose I should let him comment.
Easier to explain through Esperanto's "Netusxebla Fundamento", actually. — nitcion.
Especially considering that hardlinerism isn't the same as fundamentalism, which is what the sort of thing you're postulating would engender.
Okay, then fundamentalism. The forward to Esperanto's "Fundamento" says: "The Fundamento must stay strictly untouchable, even along with its errors." (La fundamento devas resti severe netusxebla ecx kune kun siaj eraroj.) This may be very sensible for Esperanto, but it's just plain silly for Lojban.