Living in the "Bible Belt", I never even had an idea that anyone in the world had a problem with it...until the internet entered the scene. Then, it seems, the movie was this big deal just because of the recitation of a few lines from the Bible.
I don't get the whole "I'm offended by it, so YOU have to stop it" idea, anyway. There's PLENTY on TV that offends me these days, and I respond by...wait for it...turning the channel. It's Charlie Brown, for goodness' sake. It is just about as inoffensive a cartoon as has ever been made. The same people who complain about A Charlie Brown Christmas probably also watch Adult Swim on Cartoon Network. That stuff is as offensive as it gets (on a cartoon station!), but I respond by blocking the channel.
Funny, I didn't even have to go to court, or try to take it away from someone who, incomprehensibly, enjoys it. Now I can focus on the things that are important to me.
And, to agree with Jay, The Charlie Brown specials all gave me an appreciation for jazz that I'd never had before. Not that I ever disliked it before. I had simply never really been exposed to it. I love the music for the Charlie Brown specials!