I wonder if this is not related to when these sects developed, rather than any sort of theological issue.
I think that’s right.
I agree Bluegoat.
It doesn’t seem like an indictment of the KJV that it was translated in 1611, thus available at the time when these groups got their starts. As for the contention that “orthodox Christians” tend to use modern translations, it would seem that the author has forgotten which Bible John Wesley, Charles Spurgeon, Dwight L. Moody, and many other “orthodox Christians” of Engliush descent used until the modern versions appeared. Virtually all non-Catholic “orthodox Christians” of English descent will be found to have begun with the 1611 AV (Authorized Version).
I am Catholic, and use the Douay-Rheims almost exclusively. But I am a convert and most of my memorization is from the KJV. I cannot see how it in any significant way hinders anyone from being a non-Catholic “orthodox Christian”.
The KJV is the Bible that a LOT of us grew up on. I know that I did.
And remember that there was daily Bible reading (from the KJV) in the public schools in the USA for many, many years…Even people with little or no religious background were hearing it read, if they never cracked a Bible open in their lives.
To many, KJV was simply THE Bible.

In many homes, it was the only book that folks owned…Books were rarer, they cost money, & there were many who could scarcely read at all.
Given all this, it would be strange if it were any other translation that various groups battened on.
Interestingly enough, however, when the earliest English settlers came to America for “religious freedom”, what they meant by that was “freedom from the KJV”. It was the new-fangled, “modernist” version of its day, and religious conservatives wanted their old familiar [Geneva, Bishops’, Tyndale, etc] back again.
The more things change, the more they stay the same…