Since I'm a Canadian, I'm probably not wired into the discussion that seems to be happening here. There seems to be two problems being argued here in the reviews:
1) The current legal decisions that public money can not be used to fund any particular religion. This is an ongoing area of dispute as governments at all levels attempt to determine what constitutes an establishment of religion.
2) Various non-government organizations attempting to use as inclusive a term as possible.
Since the first item is legal issue that depends on the way that the US Constitution is read and affects how governments spend tax dollars, it doesn't have much to do with what the greeter at Walmart says. And that, it seems, is where the current discussion is focussed.
And I'm not clear what the fuss is. I agree, some things are dumb: It's not a "Holiday Tree", it's a "Christmas Tree" just like "Turkish candy" and "French fries" are what they are called.
However, at the risk of pointing out the obvious: Walmart is not a Christian organization. Nor are governments--people are Christians, not organizations. It's not surprising then that, as a business rather than a Christian organization, Walmart might choose to greet customers with a term that includes as many of their customers as possible.
There also seems to be a misconception that people avoid saying "Merry Christmas" because they don't want to offend others. Let me use an anology: My mother brought me up to show good manners and respect to others. No one who uses "Happy Holidays" is suggesting that others will be offended by using "Merry Christmas" (at least, no one with a brain). In the same way, I use "Please" and "Thank you" not because their ommission will offend anyone but because omitting those courtesy terms shows a lack of respect to others. In the same way, I might use "Happy Holidays" to those of my friends who are non-Christians as a way of showing respect for their traditions (even if I don't share them). I suspect that commercial organizations follow the same line of thought. It's not offending others that worries them so much as showing some respect for other's differing beliefs.
In fact the only people who seem to be offended in this discussion are those who insist that everyone must wish them a "Merry Christmas." It seems to me that insisting that people say "Merry Christmas" because 85% of the population is Christian is an odd thing to demand in a nation that values free speech. It seems to me that insisting that everyone who enters Walmart be greeted with "Merry Christmas" because I'm a Christian is--well--un-Christian.
I think I must be missing the point.