Old Fat One: in my experience, we normally do/did make that accomodation.
What's at hand here is the matter of public law.
Not just the USAF is so bound, as far as I can tell, but it seems that the USAF has chosen to go after the letter of the law for their own reasons.
Point First:
The Enlistment oath and officer's Oath of Office both contain this phrase. {So Help Me God}
Normally, it is not required to be said if the speaker has a personal or moral objection, as is true of all oaths administered by the United States government.
However, a change in October 2013 to Air Force Instruction 36-2606 made it mandatory to include the phrase during Air Force enlistments / reenlistments. This change has made the instruction "consistent with the language mandated in 10 USC 502".
Point Second:
§ 502. Enlistment oath: who may administer
(a) Enlistment Oath.— Each person enlisting in an armed force shall take the following oath:
"I, XXXXXXXXXX, do solemnly swear (or affirm) that I will support and defend the Constitution of the United States against all enemies, foreign and domestic; that I will bear true faith and allegiance to the same; and that I will obey the orders of the President of the United States and the orders of the officers appointed over me, according to regulations and the Uniform Code of Military Justice. So help me God."
(b) Who May Administer.— The oath may be taken before the President, the Vice-President, the Secretary of Defense, any commissioned officer, or any other person designated under regulations prescribed by the Secretary of Defense.
I suspect that if this ends up in the Supreme Court, the "normally" mentioned above, which was a custom with long standing, will probably be codified into a regulation of some sort to accomodate those who have no religious belief.
Freedom of religion and freedom from an official state religion are both addressed in the First Amendment to our Constitution.
PS: your reference to Americans as "spams" appears deliberately offensive, and I'd ask you to be more polite in the future. Sort of like the casual habit of referring to folks of African descent as "coons," ya see ... I realize it's a long British habit, and common among certain Yank bashers on this forum, but I invite you to get into the year 2014, no matter how old or fat you are. (I am becoming more of both as each year passes, it seems! )
EDIT: For those interested, the standard Department of Defense Enlistment papers, which include the oath, is on line here:
DD Form 4.
EDIT 2:
Sun Who, there is a small and very vocal evangelical minority in uniform who are quite outspoken in such matters. There were when I first entered the service in the 70's, and still are. That is what comes of having citizen soldiers: the new troops/sailors bring their beliefs with them. I wish some of those evangelical folks would appreciate that our non-believing comrades in arms do likewise.