Why people like you last in jobs dealing with the public is totally above my pay grade to determine.
Why people like you haven’t become mountain men is beyond my pay grade. Really, you are demonstrably pointlessly angry. Really it’s just plain stupid to get upset about this. Here’s the real base level of what happens:
Guy does something for you
You say thank you
They indicate that what they did for you was not a problem
You get pissed
Step 4 there ONLY happens if you’re one of those morons who goes through life looking for anger. As you said: it’s not all about you, you are not the enchilada. Get over yourself, accept the fact that you were apparently not difficult to serve, and move on with your life.