Problem is, this isn't quite true, since the following ad features dancers singing a ditty that clearly contains the word Christmas, and given top billing, to boot.
"Go Christmas, go Hannukah, go Kwanzaa, go Solstice... do whatever you wannukah, and to all a cheery night."
Personally, I don't find anything offensive about the ad, though I know there will be some who take issue with the fact that it includes other holidays. I will be the first to criticize how pc this world has become, but there is a difference between being pc and being inclusive. Christmas is not the only celebrated holiday during the December 'holiday season', and it's not as if the Gap was excluding Christmas or calling it something it isn't. Yes, it's stupid to call a Christmas tree a Holiday tree, that indeed is being pc, but to wish someone Happy Holiday's is not pc, since not everyone is Christian.
Let's all be more charitable during this Holiday Season. Since that's what the season is all about. Isn't it?