Because sometimes Jews put up a tree to be fun and festive but not to celebrate Christmas?
If you're going to appropriate another ethno-religious group's tradition, then either do it or don't do it. I don't care what religion you are and whether or not you celebrate Christmas. If you're putting an evergreen tree in your house and putting lights and decorations on it in December, you have just put up a Christmas tree. Sorry. Deal with it.
Funny you talk about appropriating traditions given that the Christmas tree arguably started as a pagan Germanic thing, not a Christian one.
