We just had a controversy here in Washington State over whether to call the public school break at Christmas time "Christmas" break or "Winter" break. I truly believe that the people who don't want anything religious mention is because they are afraid that someone close to them may turn spiritual. And to them, that is a no no. So the best way is to fight anything that resembles a belief in an Almighty God.
That's sweet and all, but since the *majority* of Americans who subscribe to evolution are *Christians*, it appears that your conspiracy theory falls quite flat.