When I celebrate Easter or Christmas, things like decorating the tree and coloring eggs have nothing to do with worship or worshiping around that time of year, and I don't think anybody would say that they do. (Well, you can alegorize, make similes, and whatnot. Like the Resurrection eggs that can be used to teach the story of Jesus' sacrifice to children. When I was a kid, the private school I went to and my Sunday school class used those, and I still have a set of them myself that my family used to use in our daily devotions on Easter. I personally don't have a problem with it, but some may disagree. And that's fine.)
Worship itself it spent reflecting Jesus' birth or sacrifice, as well as a reminder that those are things we should be celebrating in our hearts all year long. It can be a time of spiritual renewal and reflection, to look where you're at in your Christian walk and make adjustments as God reveals.
In any case, the Bible calls for mutual respect on both sides, over things that are debatable and not clearly defined in the Bible. If neither side can retain mutual respect, then it only causes division and would be best for one person or the other to just leave the subject alone or refuse to debate it, IMO. Otherwise, discussion is good, especially for those who are undecided or rethinking their position.