luna- ”it is plain rude to ignore someone when they speak to you.” i do not greet men with good shabbos personally. However, if he initiates the greeting, i do respond in kind though!
Feel free to take me to task on this part, but i dont greet strangers during the week, whether male or female. I will sometimes smile or nod, but thats it. Shabbos is my exception in ‘don’t talk to strangers’, so i greet females, but not males or non-jews. Maybe thats just my comfort level though.