Not that they aren't important or valid, just that the prevailing culture won't dedicate any resources for tribute.
Your world must be very small, if you aren’t willing to share it with anyone from a different religion. I thank G-d you’re not my child’s teacher.
What you should do, is thank God that you live among a majority culture of Christians of European descent, because we are the creators of the concept of majority rule with minority rights and the most consistent practitioners of government of that form.
And if you have any doubts, ask yourself why the world of all religions and ethnicities is beating down the doors to live among us? If we're so bad as minority religions and ethnicities have portrayed us in the media and academia, then why does everyone follow us wherever we go (US, Australia, Canada, etc.)?
I’m sorry if I sounded harsh, but I don’t think it hurts to recognize in a school that there is more than one religious holiday happening at the same time, talk about the reasons why, and make Jews and others feel welcome by recognizing their religions, too. Trust me, the Jewish kids I have worked with were well aware they were members of a minority, surrounded by Christians. They felt honored when people actually bothered to recognize or acknowledge their traditions. I feel that it’s the friendly, caring thing to do, especially in a school. And I don’t think substantial resources are expended in teaching kids to sing “The Dreidel Song” as well as “Jingle Bells”.