There are some caveats to it > The legacy SCP protocol (selected by the -O flag) requires execution of the remote user's shell to perform glob(3) pattern ma

There are some caveats to it > The legacy SCP protocol (selected by the -O flag) requires execution of the remote user's shell to perform glob(3) pattern matching. This requires careful quoting of any characters that have special meaning to the remote shell, such as quote characters. so I guess it is defending about theoretical problem where you use sftp-compatible quoting that silently breaks if you use same commands against scp script, still would be nice to have global config for scp fallback.