What good will banning Santa bring? That would just bring more divisiveness than unity. People would be on the defensive and no one would be willing to listen to each other. Either side--those who believe in Santa and those who shove it down other people's throat--are being highly ethnocentric. And both sides are missing the point of the holiday season.
The whole point of the holidays, commercialism aside, is to remember how lucky we are to have been blessed with our gifts (not to be confused with the material presents we give and/or receive) and talents. Gifts and talents that ideally should be put to use to better the world.
The spirit of Christmas is grace, generosity of spirit and goodwill to everyone. It really doesn't matter whether Santa exists or not because goodness is real. I believe he exists because generosity and love exist everywhere, we just have to find it within ourselves and those we encounter. If anything, we need more people like Saint Nick in our modern society; people who are willing to give up everything to help those in need. Imagine the kind of world that would be.
However, as dreamer fighting cynicism I digress because I realize that debating certain ideas with people is futile. There are always two sides to every argument--the side that is right and the side that is right. And in the meantime, the world turns as people continue to die of hunger, or from perfectly preventable (or treatable) infectious diseases, while the lucky few have the luxury of debating epistemology from the comforts of our homes or cubicles.