The Obama administration has directed the military to not allow personnel to say “Christmas”, in spite of the holiday’s status as a federally-recognized holiday.
The reason given by armed forces officials is that not everyone celebrates Christmas and that out of respect for them, military members should refer to Christmas celebrations simply as “holiday”-themed festivities.
This prohibition comes in the context of a wider push for political correctness in society in general and the military in particular, as evidenced by the recent reprimanding of Navy Chaplain Wes Modder for simply discussing religion, as chaplains are wont to do, with military personnel.
See how servicemen have reacted to not being allowed to say Christmas at the link below:

Lol anti christ and satan lol yet you expect to be taken seriously lol sad really
Yeah right chief!!! Merry Christmas!
Then say Happy Christ birthday!
More proof he’s not a Christian!
Merry Christmas, Islamist jihadist!
No doubt You are a Brain-Washed, Blinded, Liberal, Demoshit Obama supporter Buddy Bryant.
http://www.snopes.com/obama-military-christmas-ban/
Not a fan of Obama, but this one isn’t true
Snopes says this is false.
MARRY CHRISTMAS AND