I wish courtesy was SOP. We live in the kind of world where anything out of the ordinary is extraordinary, especially when it comes to something as small as common courtesy. Whenever someone demonstrates a cordial gesture towards me, I am honestly floored. It just goes to show how rare an act of human generosity truly is. I think our culture is a bit twisted. Often we rail on about the things that annoy us instead of focusing on the things that give us cause to celebrate, and when we do celebrate, it's usually at the expense of someone else.
People should just be nice. Being the better man usually means going against that thorny thing called pride. So what if you're insulted? You're better than that. In a way, being the "better man" is also a form of pride.
Some of us just haven't leveled up our pride that high yet.