Some shopping centres in some of the country's bigger cities took down "Merry Christmas" and replaced it "Happy Holidays", so that non-Christians won't be offended. Before the political correctness factor popped up some years back, either greeting, plus others, were typical without one giving a second thought to it. There's a sense, to me at least, that using neutral greetings like "Happy Holidays" is equated with "knowing better". Memorial Universitys greeting on Christmas Eve is "Best Wishes for Personal Growth in the New Year." Nothing wrong with that or other neutral greetings. On many Canadian Universities, you won't find the word Christmas on the front pages at least. On this Christmas Eve some have no acknowledgment of Xmas or the "holiday season" at all, and some have "Seasons Greetings".
There is nothing inherently offensive about saying Merry Christmas. It really just means "good wishes to you", or "enjoy the Christmas holidays". With over 70% of Canadians being Christian of some stripe, there's a good chance the greeting Merry Christmas will resonate with most. The fact is that Dec. 25 exists, it's a birthday of a special and good person, and from what little we do know, he lived an exemplary life, which is cause for celebration. You don't have to be religious to appreciate that.
Many public organizations like tv stations, universities, and governments will say something more general or nothing. From their point of view I guess it is less confusing to avoid a specific religious greeting as they could get pressure from other religions to display a specific religious greeting for their special times of year. Then it can get more complicated since the number of occasions can become numerous and imposing on broadcast and web space.
On the other hand, one could ask, "what makes the holiday?" Answer: Christmas, so why not say "Merry Christmas". The Telegram did today.
There are people who don't care for any type of organized religion, and those that grew up with the tradition and still partake to some degree or other. If you see or hear a greeting that does not apply to you, ignore it. Different religions have their own special days, and accordingly they like to wish each other some related greeting. That sure doesn't offend me. They can display it any window, or say it anywhere. No offense taken. If Walmart wants to display "Happy Hanukkah", "Happy Eid", or "Happy Diwali", that's perfectly fine. These holidays don't apply to me but they do apply to someone, and everyone is entitled to celebrate whatever it is that is important to them.
In a multi-cultural society, it's a given that there are special days to all. "Merry Christmas" should not be viewed any differently.
What is offensive is hearing on radio stations, "Don't worry, you still have "X" number of weeks to shop." If anything should go, that's it. However, as long as the word "Christmas" keeps selling stuff for business we'll be hearing that again. Anyway, don't worry, there will be 10 months to go before you hear that again, 11 if we're lucky.
Merry Christmas (i.e., best wishes) and have a safe holiday.