It doesn't look like everyone in this thread uses the same format.
Some posts appear to have the lines broken up at less than 80
characters,
Not some, most.
while other posts appear to have the lines not broken
up at all.
Very few, the exceptions to the rule. In fact if you use
Google to search for "usenet rules" and click the first link
(if not other links..) you will see this, the 80 characters
mentioned.
So what is the purpose of the "quoted printable" format?
It has none on usenet, unless you are on a private news
server, a private forum that has specifically deviated from
the usenet conventions. More commonly it is used to
deliberately not have hard returns, line lengths until the
end of paragraphs which might be desirable in some use but
not usenet.
Why does the software offer it if it's not supposed to be used?
Because the author wasn't acting responsibly? It's a
feature but the same can be said about any feature in any
software. For example, In MS Word you can change the font
size to 150, but does this validate it for a specific use?
Of course not, it's far too large for most uses then. Same
goes for any other software feature, that it exists is not
evidence that it is appropriate for any particular use.
Anyone can put literally anything into software. If the
author had put in a button that logged into a government
server and tried to hack it, would THAT be ok too? Of
course not.
Usenet is not based around one lone newsreader, it is
deliberately and purposefully designed to be accessed by
many many different machines, readers, etc. What your
particular newsreader can or can't do, doesn't change usenet
conventions. It might be able to hide text inside images
and decode them again but would it mean you can converse on
usenet in general with only these pictures with hidden
text? No.
