Being polite costs nothing. It really shouldn't be out of the ordinary.
Even if I wasn't a communist, the first things I learn at any job are how I can hook up people who are nice to me and how I can fuck with people who aren't. It's in my self-interest to be nice to employees that mostly have that same choice. I will literally do hundreds of dollars worth of free work for a customer if they're nicer to me than my boss is because doing so fucks over my boss.
I don't go out enough to feel this but as someone who worked as a waiter there were a couple times where I'd have a customer that genuinely made my day better
First job was at a fast food place. One day, a car at the drive thru was hurling abuse, threats at the cashier. Manager of the restaurant made sure their order was ready as quickly as possible. Then, as a bunch of us watched, she opened each burger and spit on each one, smeared it into the bread so it wouldn't be noticed, rewrapped, and then handed them to the customer personally.
That's when I learned to ALWAYS be polite to the people who prepare and serve your food. And to always open up a burger or sandwich b4 I bite into it.
I've worked enough years in retail that at worst I have sympathy for a worker having a bad day.
Never had an actually hostile experience with a service worker that wasn't actually just the worker having a bad day.
