I'm happy when friends remember me at the holidays. If they are friends, they will know that I'm a Reform Jew and not send me a Christmas card. A 'Happy Holidays' card is fine. I'm not trying to make the 2 events equal, I just appreciate the sentiment.
If someone didn't know I was Jewish and sent a Christmas card, I'm not going to be angry. Being black, people make assumptions. I get all kinds of Kwanzaa greetings from idiotic white people. If they knew anything about the history of Kwanzaa or its creator, they wouldn't even bring up the subject with me.
Several years ago a co-worker gave me a nicely wrapped present. She explained that she and her family were Hindu and didn't celebrate Christmas. Well, I didn't want to be rude and tell her I don't celebrate Christmas either, so the next day I brought a gift for her. :)