"Iso-2022-jp" was removed from MIME, and there were no public
protests, partly because there are so few Japanese on this list, but
also because the Japanese will continue to use their JUNET encoding
for some time, no matter _what_ MIME says.
No, Iso-2022-jp was removed for the same reason mnemonic was removed,
lack of a published specification acceptable to the IESG for citation
within the MIME document. It had nothing to do with the presence or
absence of Japanese on the list.
The fact that both Iso-2022-jp and mnemonic had an established history of
use within some part of the Internet is why the working group tried to
include both. I doubt that many of us who supported this inclusion are
amused by all the invented reasons for their exclusion.
Jim