What does "political correctness" have to do with anything?
If someone prefers that the term "Happy Holidays" be used in place of "Merry Christmas", it's because Christmas isn't the only game in town at this time of year - which means that "Happy Holidays" is perfectly accurate, not some attempt at covering the PC bases.
And just so ya'll know - all you Christians who celebrate Christmas - you're celebrating a stolen holiday. That "Christmas" tree you like so much? Yeah, that's a Yule tree. How about the mistletoe? Sorry, that's got it's roots in Norse mythology and Druidism. What about presents? Oh, those were first started by emperors in pre-christian Rome. And did you know that there's absolutely no evidence of Christ being born on the 25th of December? That's because what is now Christmas used to be the concluding date of the Pagan festival of Saturnalia, and was only transformed into Christmas in the 4th century or so in order to make it easier for the missionaries attempting to convert the local pagans to sell Christianity to them. But hey, ya'll stole it all fair & square so it's totally cool to call it Christmas, and get all huffy & self-righteous when someone points out the fact that there are other options out there, right?
Don't get me started on Easter or Halloween, either.
My point - stop whining when someone asks that you wish them a Happy Holiday rather than a Merry Christmas. Like it or not, you're not the only game in town. Show some respect, and understand that there are people out there who don't celebrate the way you do. Seasonal elitism is getting pretty tiresome.