The fact that Santa Claus takes some inspiration from Saint Nicholas or that Yule was and is now celebrated distinct of Christmas does not mean both Santa and Christmas were and continue to repurpose pagan elements. Christianity adopted many pagan elements, especially into it's holidays in order to make converting the pagans easier. Personally, I find the argument for Santa taking inspiration more from Woden/Odin more compelling than Saturn, but the similarities are certainly present for both.
While many Christians don't like to hear that their holidays and traditions were originally pagan and only adopted by the church in order to convert pagans, it is still a very valid point. Denying it so as to better appeal to that "demographic" would be dishonest.