Here's one man's answer.
Or how about this one?
And another one.
One relevant passage from this last one: "A small, well-funded, and vocal minority of Christians are unhappy with
the fact that their holiday has not totally eclipsed all others. They
want all other celebrations squashed out, in an effort to make the
season uniquely Christian, and organize protests and boycotts against
any company which promotes an all-encompassing tolerant attitude ("Happy
Holidays" vs "Merry Christmas"). American Atheists acknowledges that
such views are only shared by an ignorant and bigoted minority of
Christians, but at the same time we look to the more tolerant Christians
to quell this attitude. As it is with Islam, the health and growth of
Christianity depends on those within the church."