As far as I've been able to make out, "these people" are mainly corporations who decided that a more inclusive holiday greeting would please their customers. Wal-Mart, I believe, was one of those .
The brouhaha came, naturally, mostly from Fox, beginning a few years ago. They portrayed this rare corporate courtesy as a War on Christmas (complete with War on Christmas graphic--pow!) by the politically over-correct. No one agitated for this change; there were no demonstrations, no atheists railing against the temerity of wishig them a Merry Christness--just corporations trying to be more inclusive by wishing folks a Happy Holiday instead of a Merry Christmas.
Beck, O'Reilly & Co. added fuel to the fire by reporting that Obama had escalated the "War on Christmas" by replacing traditional White House "Merry Christmas" cards with "Happy Holiday" cards. I think that lost steam when it turned out the Bush administration actually made that change.
It's just more aggressive conservative victimhood: the liberals have all the media, the secular world wages war against us godly, the atheists don't want to pay for creches on the town green...we get no respect.
Poor bastards.
I know there's a balance, I see it when I swing past.
-J. Mellencamp
Real things always push back.
-William James