It is done to commemorate a celebration when humans moved past the need to claw each other's eyes out over smallest disagreements.
Politeness does not mean being timid, it does not mean being a walking mat, it does not mean being selfless and God-like.
It just means lack of being rude - a polite person would be respectful towards others (not to be confused with being shy or other social disorders).
It also means being assertive - and standing up for yourself when needed but without having to resort to lowest lows of personal attacks, cussing, or other demeaning manifestations.