I work as an outfitter and wish every customer safe travels regardless of gender. It’s a western way of saying namaste, good luck to you and I hope your journey unfolds in your favor. I’ve also been told to stay safe many times and it has never offended or discouraged me from doing whatever the fuck I want. In fact I enjoy hearing it, gives me the sense that somebody is on my side and sending me off with good vibes. Of course, it could be used in an attempt to passive aggressively police women’s behavior, but most often it is said with kindness.