Certainly there is the need from time to time for revision, due to the evolution in language. The English language of the KJV is very old and awkward for those not used to it. There is nothing wrong with a revision that simply brings the Bible in conformity to modern language. The problem is the plethora of modern versions flooding the bookstores are not being made simply to update the language to conform to modern use. There haven't been large strides made in our understanding of the original languages that would justify so many new versions.
The real reason for the flood of new versions is money. Modern versions have simply not had the phenomenal staying power that the KJV has enjoyed. In order to keep sales up, the publishers must constantly come out with "new" and "improved" versions in order to get people to trade in the old for the new.
However, due to copyright laws, the "new" versions must be significantly different from previous versions in order to qualify for copyright protection. Therefore, modern translators, who work for the publishers, give their new versions a good shakedown in order to make enough changes to get their copyright. Then the publisher packages it attractively, with a new slick advertizing campaign. Unfortunately, some Christians just have to get the latest and best "new" and "improved" Bible version. So much for an unchanging final authority.
Prov 30:5-6 5 Every word of God is pure: he is a shield unto them that put their trust in him. 6 Add thou not unto his words, lest he reprove thee, and thou be found a liar. (KJV)
Rev 22:18-19 18 For I testify unto every man that heareth the words of the prophecy of this book, If any man shall add unto these things, God shall add unto him the plagues that are written in this book: 19 And if any man shall take away from the words of the book of this prophecy, God shall take away his part out of the book of life, and out of the holy city, and from the things which are written in this book. (KJV)
Perhaps some of the publishers and translators of modern versions have no fear of God. One day, they are going to find out that He meant what He said in the above verses.
JCSM