"We come in peace for all mankind."
or... "One small step for man, one giant leap for mankind."
Yup, such outdated or offensive comments. /sarcasm
That being said, this particular plaque is onboard the Enterprise ONLY. And from what we know of canon (to those of us who actually still give a damn about such things), very few non-Humans were serving aboard the Enterprise. Spock being one of the exceptions. My assumption is that other ships wouldn't have the same motto, for example the USS Intrepid (a crew of ALL VULCANS).
"To boldly go where no man has gone before" is an honorific from the speech given by Zefram Cochrane in early 22nd Century, and likely adopted by "the flagships" of the Federation. Not as a motto used aboard every single ship (as we've seen other plaques which don't have the motto). Pike's remarks about women I'm perfectly okay with rewriting it (as it was indeed sexist), as well as him being a slave owner. All of which from 1 rejected pilot episode, so can be discarded. But the plaque of the Enterprise, was the same for all 79 episodes and should keep the original motto. Political correctness be damned!
Not all things in history need be rewritten, just for the sake of political correctness.
