In this cold world, a kind word is always welcome, so if one person genuinely hopes for another to enjoy his or her holiday, or wishes to greet that person in the spirit of the season, far be it from me to cast a stone. But, in the weeks leading up to Dec. 25, if you make a conscious choice to avoid saying "Merry Christmas," there's a good chance you have decided that a divine gift that was meant for all mankind, and in which billions of people rejoice each year, is too offensive a notion to cross your lips.
Yes, yes, I know -- folks say "Happy Holidays" and other insipid stuff because not everyone is Christian, so this is a way to be inclusive. But there is no inclusion to be had by euphemizing the warmest wish of a particular religion, presuming it to be objectionable to non-believers.
Of course, there are many different religions and faiths in the world. This is something folks are taught by the age of, say, four or five. So, if you are older than this, yet you eschew "Merry Christmas," what you are putting forward is that one of the world's religions is uniquely unsuitable for public acknowledgement.
No one frets about being "inclusive" during Passover or Ramadan, nor should they. Ironically, the purported inclusiveness of the "Season's Greetings" police is actually about exclusion. To wit, it's about excluding just one religion, Christianity, from any rightful place in modern society.