@hisham_hm it messes up editor commands that operate on the end the line and you don't know it's there until the cursor goes to the wrong place, and once it's there it can't be removed without cluttering up the log
your history seems off too, for starters whitespace isn't lost when emailing diffs, and other projects disallowed trailing whitespace long before git happened, eg. freebsd added it to their style(9) in 1997 and it would have been an informal guideline long before it got added
@hisham_hm no? at least mutt, mail(1) and mcom don't
@vi IIRC this was an issue not with MUAs but with MTAs. A mention I could find was here but I didn't search too hard: www.w3.org/Protocols/rfc1341/5_Content-Transfer-Encoding.html
@hisham_hm sending inline patches as quoted-printable has always been discouraged or completely disallowed by pretty much every project that uses inline patches
@vi on diffs via email: not in attachments, but inline they do, don't they?