why would anyone get upset by hearing happy holidays or merry xmas or happy hannukah or joyous kwanzza? each of those are just well wishing, not telling one person that they have an inferior holiday.
the people who are "taking back christmas" by getting pissed off at people for saying happy holidays need to all find something to do with their time. maybe be actual good christians and be nice to people regardless of how they wish you a happy holiday season.