At this time of year, people seem to go out of their way not to wish you a Merry Christmas. Instead, we hear “Happy Holidays” or “Have a wonderful holiday.” Is it inconsiderate of our Jewish, Muslim, and non-Christian brothers and sisters to wish them a Merry Christmas?
Suppose a Muslim approached you and told you to have a "Blessed Eid!" Would you feel it inconsiderate of this Muslim to presume you celebrate a Muslim holiday? If that is the case, perhaps you can understand why many non-Christians prefer not to be told to have a "Merry Christmas!" If you know someone is a Christian, it is appropriate to say "Merry Christmas!" (Just as it is also appropriate to say "Happy Hanukkah!" to someone you know is Jewish.) If you do not know the religion of the other person, then it really is more considerate to say instead "Happy Holidays!"