Though he was a saint the symbology has been non-religious for some time. It's not just Christians that celebrate with Santa. In fact, most of the non-religious people I know celebrate with Santa. Even when you tie it to a saint the overall meaning of Santa has nothing to do with God or Christians.

People like to be offended and will ruin things for other people. It's sad that we're in such a sensitive society but tolerance isn't what is practiced, sensitivity is.

As a Christian I find the idea of Santa offensive, honestly. Santa and his powers (as presented in media) are a replacement for God. I'm not going to go crying to anybody because they have Santa as an icon.