Why doesn’t anyone ascribe this certain “fictitious” purity to any other translation?
That's a very good question, one that is difficult to answer.
My thoughts are that, just as the Jews of Jesus' time were looking for a king, with all the rank and privilege he would have, the people who "worship" the King James translation also ascribe a "royal" status to their translation that simply wasn't there.
In my opinion, they try to feel hyper-religious because their Bible doesn't read/sound like the language we use today. It is beautiful language, but that's not an accurate rendition of the languages the Bible was written in originally.
Finally, when you read something like Luke 14:7-11...
KJV...
7 And he put forth a parable to those which were bidden, when he marked how they chose out the chief rooms; saying unto them.
8 When thou art bidden of any man to a wedding, sit not down in the highest room; lest a more honourable man than thou be bidden of him;
9 And he that bade thee and him come and say to thee, Give this man place; and thou begin with shame to take the lowest room.
10 But when thou art bidden, go and sit down in the lowest room; that when he that bade thee cometh, he may say unto thee, Friend, go up higher: then shalt thou have worship in the presence of them that sit at meat with thee.
11 For whosoever exalteth himself shall be abased; and he that humbleth himself shall be exalted."
It is difficult to understand -- it must be re-translated in one's mind -- and the formatting is ridiculous. it is as far from the Greek original as you can get.
A much more accurate and understandable translation is "When he noticed how the guests picked the places of honor at the table, he told them this parable: “When someone invites you to a wedding feast, do not take the place of honor, for a person more distinguished than you may have been invited. If so, the host who invited both of you will come and say to you, ‘Give this person your seat.’ Then, humiliated, you will have to take the least important place. But when you are invited, take the lowest place, so that when your host comes, he will say to you, ‘Friend, move up to a better place.’ Then you will be honored in the presence of all the other guests. For all those who exalt themselves will be humbled, and those who humble themselves will be exalted.” (NIV)
or
" Then when Jesus noticed how the guests chose the places of honor, he told them a parable. He said to them, “When you are invited by someone to a wedding feast, do not take the place of honor, because a person more distinguished than you may have been invited by your host. So the host who invited both of you will come and say to you, ‘Give this man your place.’ Then, ashamed, you will begin to move to the least important place. But when you are invited, go and take the least important place, so that when your host approaches he will say to you, ‘Friend, move up here to a better place.’ Then you will be honored in the presence of all who share the meal with you. For everyone who exalts himself will be humbled, but the one who humbles himself will be exalted.” (NET)
The last is from my favorite translation, one of the reasons being the extensive footnotes that accompany the text that explain alternative translation choices and illuminating cultural notes that help immensely with accurate understanding. You can read the passage above (with footnotes) here:
https://www.biblegateway.com/passage/?search=Luke+14&version=NET