If they don't like Christianity nor want to follow their rules they are perfectly free to start their own religion.
In many ways, they already have. It is the modern form of paganism known as Secular Humanism. They are now out to make it the official religion of the U.S. demonizing everything Christian, and outlawing the open public expression religious beliefs. Their mantra about the separation of church and state is a thinly disguised effort to see that only these secular pagan elites are able to express their beliefs.