@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