I would like to ask the same question for auto-compression-mode too.
What is the reason not to turn it on by default? How often people
visit compressed files for editing without uncompressing?
I often save a buffer of compressed data into a file name FOO.gz.
If Auto Compression mode is enabled, it does a second compression.
So I have to turn off Auto Compression mode for that.
It would be nice to make Auto Compression mode DTRT in that case.
Maybe then there would be no reason ever to turn it off.
Can anyone see a way to do this?