They lose freedom of speech when serving America?
Yes actually you do.
The Military is not a democracy for obvious reasons.
“Any commissioned officer who uses contemptuous words against the President, the Vice President, Congress, the Secretary of Defense, the Secretary of a military department, the Secretary of Transportation, or the Governor or legislature of any State, Territory, Commonwealth, or possession in which he is on duty or present shall be punished as a court-martial may direct
This code was in effect when I served in the early 70’s and I am sure long before that. There are serveral other codes that could have applied in this case.
What are the obvious reasons?
Unfortunately it probably will be a democracy before long with the continued social experimentations that are ongoing like the repeal of DADT etc.