Probably because when it comes to religions, Judaism is somehow the least offensive.

I mean, when you look at Hanukkah specials, even kids specials, they always discuss the religious aspect of the holiday, yet, on the same token, if you try to discuss the religious aspect of Christmas, it's "offensive"... I was surprised that nobody complained about SESAME STREET had a nativity pageant for a holiday special over ten years ago. Other than that, A JOHNNY BRAVO CHRISTMAS briefly mentioned that Christmas is the birth of Baby Jesus, that much I can remember.

But again, I think it's mostly because Judaism is somehow the least offensive religion there is, maybe because there are so many Jews in entertainment business? I don't know... I always found it interesting with so many Jewish writers and producers out there, that if they write religious characters, they write them as Roman Catholic, but I digress.

Another theory is that Christianity is perhaps the most common practiced religion among Americans, so they're probably wanting to teach more about Judaism and bring more attention to it, because let's face it, when it comes to all the major holidays, the likes of Passover, Hanukkah, Yom Kippur are always overshadowed by Easter, Christmas, Thanksgiving, etc...