If something is obviously not meant to be offensive, but by some coincidence it is, then we should be offended by it?

One day I hope to live in a world where people judge text by what it means, not which particular squiggly patterns ended up on the screen...

No, you're wrong. "man" is the obvious abbreviation for "manual" when trying to reduce the number of characters used. Not once as a teenager learning unix shell commands did gender (or cultural stereotypes) enter my mind when using the 'man' command, but I guarantee it does when looking at the 'bro' command.