The idea of a Polite Society has basically gone away. Because, there are no immediate consequences for any public action. A rude person in public can get away with telling a stranger to go F' themselves! A politician can lie, cheat and steal and get re-elected!
I also try to go to Walmart during off hours. Within reason, I will go to a specialty shop, pay more, if it avoids a crowd. I go to movies weeks after the debut and only on off hours! You couldn't make me go to a mall. I park at the end of the lot and walk. It's my Cheap Bastad gym membership. And if being tailgated, while driving 7-10 over the speed limit, I will usually pull over if some one wants around that bad.
But as Marine General Mattis said, "Be polite, courteous and professional at all times and always have a plan to kill everybody you meet. " And when confronted with violence, "I come in peace. I am armed. But I'm pleading with you, with tears in my eyes: If you F' with me, I'll kill you all."
The important thing here is, don't let it make you change your attitude! Be kind courteous and professional...