I really don't get it

Yes, I like my Christmas parties and my trees and all the decorations, and loved singing the carols in school (and watching young kids sing them now), but... I'm a Christian. If I were Jewish or Muslim or an atheist, I'd have serious problems with my kid being in a Christmas pageant in school, since it is a religious holiday and it wouldn't be MY religious holiday. Perhaps a pageant for all the faiths might be better, but still. Is it just me, or why can't people understand how insulting all this would be to someone who isn't Christian?

Ok, here's your chance to speak out, all your non-Christians (and Christians too). Am I wrong? Isn't this all a bit insulting to non-Christians?