> This sounds off; the KJV was written in an intentionally archaic style, which guarantees that, at the time of writing, popular understanding of some of the usage would have already diverged from the meaning as written.

This is frequently stated but when it gets down to brass tacks seems to be somewhat exaggerated as the source of all archaisms from the POV of later readers. From what I can tell, while some things (like second person pronoun use) where archaic at the time of writing (and egregiously bad choice of archaism because they created distinctions not made into the source material by using a distinction no longer currently in use in English, either), many others were things that were in transition at the time of writing and which didn't reflect later (and also, in some cases, earlier) common usage (thereof to avoid possessive pronouns as gendered ones relating to inanimate objects were on the way out, but “its” was still not firmly caught on).

But I didn't say every archaism in the KJV was due to an intentional style choice. I said the KJV was intentionally in an archaic style. That fact makes it strange that "this is archaic usage" would be considered a problem in the KJV, regardless of whether the particular archaism was written to be an archaism or just developed into one.

> gregiously bad choice of archaism because they created distinctions not made into the source material by using a distinction no longer currently in use in English, either

All the source languages for the Bible have a second person singular/plural distinction. Or did you mean something else?