Why not? It is that time of the year again. It is a custom I grew up with. It is a widespread practice in the country in which I live.
So, does that mean my seasonal good wishes are intended to apply only to people who share a similar cultural heritage?
Actually, when I think about it, most of those who share a similar cultural heritage will probably think I am just hoping that they enjoy the customary things that many of us enjoy at this time of year - attending parties, going on holidays, preparing for celebrations, meeting with family members, exchanging gifts, feasting, getting “merry” etc.
Even if none of that applies to you, I still wish you a merry Christmas. No-one is excluded from the sentiments of the Christmas message: Peace on earth and goodwill to all. (That might or might not be an accurate translation of relevant scripture, but it is the one I read on Christmas cards – and it is good enough for a non-church-goer like me.)