Xians is misspelled as Xtians.
Supposing this to be in the right forum, the OP seems mistaken. I can’t see the term “xians” in the threadspotted thread. But the term “xtians” does appear.
Er, that’s his point.
Whether it is an error is another matter entirely. My feelings - a plague on both their houses. (I have no love for the abbreviation, however it be spelt - or spelled).
The X subs for Christ, doesn’t it? Therefore "Christ"ian should be "X"ian. Otherwise, it says Christtian.
Personally, I feel it’s stupid no matter which way you spell it.
Both spellings seem to be common. I personally prefer the “Xtian” spelling, because when I see the “Xian” spelling I automatically parse it as the Chinese word and then get all confused.
Both sound to me like UFO cults.
I think both are? 
Xtians are fans of the band X, and the television series The X Files. Confusing them with Xians brings on enormous theological confusion. Chinese Xians probably are something altogether different.
To remove any confusion, let’s adopt a new spelling, in honour of Lib: [post=6760826]Xinanes[/post].
Those Christtians chap my hide also.
dictionary.com: xian
3 entries found for xian.
[ol][li]Xi’·an also Hsi·an or Si·an[/li]A city of central China southwest of Beijing. The capital (221-206 B.C.) of the Qin dynasty, it is a major commercial center and the capital of Shaanxi province. Population: 2,872,539.
Source: The American Heritage® Dictionary of the English Language, Fourth Edition
Copyright © 2000 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
[li]xian[/li]n : a city of central China; capital of ancient Chinese empire 221-206 BC
Source: WordNet ® 2.0, © 2003 Princeton University
[li]xian[/li]XIAN: in Acronym Finder
Acronym Finder:
What does XIAN stand for?
Christian[/ol]
dictionary.com: xtian
1 entry found for xtian.
[ol][li]xtian[/li]XTIAN: in Acronym Finder
Acronym Finder:
What does XTIAN stand for?
Christian[/ol]
Advantage: xtian, less ambiguous
I’ve contacted the Acronym Finder and informed them of their error. Obviously, “Xtian” stands for “Christtian”.
I think it stands for Crosstian.
Or Cruztian. 
The Acronym Finder allows people who encounter a term they don’t recognise to find out what the person using it meant by it. That someone thinks that term was ill-used is otiose - regardless of whether the person of that view was informed by great expertise or aliens-run-Denver-airport nutbaggery.
The thread selected for threadspotting used some term. The link for threadspotting accurately reflected the thread’s use of that term. That Liberal doesn’t like the term doesn’t mean there’s an error on the front page.
So it’s other forum stuff, then. Posting in the original thread would probably be taken as a risible hijack, so… oh. Pit, then.
I’m glad I didn’t bring up something more critical, like an unclosed tag or something. There might have been vein popping.
My first name IRL is Christian. I had sunday school back when I was twelve or so. We had notebooks and when I got mine back, the teacher had written “Xian” on it. I was a bit confused for a while . Got it eventually though.
/hijack
You asserted there was an “error.” Your assertion has been challenged. I’m not sure why you find that surprising. 
Our society is really going to heck in a handbasket. We need to put the X back in Xmas.
“He changed his name from ‘I believe in something, but I don’t really go to church…’”