Every year, without fail, some people get offended that they are not wished a "Merry Christmas". Instead, they hear "Happy Holidays", or something else, and this is supposedly very wrong.
I used to hop aboard that same bandwagon. It was almost like... I felt I was being robbed of Christmas spirit, or something. Denied my right to have a Merry Christmas.
Over the years I have come to realize that it doesn't really matter what we say.
We're Canadians. We're multi-cultural. If you want to say Merry Christmas, go ahead. If you want to say Happy Holidays, go ahead. If you want to say Happy Hanukkah, go ahead. If someone gets offended by whatever you choose to say, that's their problem.
Christmas spirit is what you make it. Say whatever makes you happy. If you choose to say nothing at all, that's fine too. Life is too short to be upset over something so trivial, and you do get upset by it, then you are ruining your own Christmas spirit.
When it comes to Christmas, there are no rules... except maybe holding the door open for that person whose arms are full of gifts for their friends and family. :)