Because your obligations would be rootless. But Richard Dawkins is ok. I have a few disagreements with things he believes but overall I really like him and I find anything I disagree with to be entertaining if nothing else. (If that is where you got the name Dawkins2010, if not, I apologize)
Back to the point, If you take any obligation without having anything to base it off of, it isn’t really binding.
On another note, I don’t believe people can actually be an atheist.Speaking scientifically, you just cannot know for 100% sure either way. To proclaim atheism takes a lot of faith. I am not speaking about religion itself, just the psychology behind the thinking. I might add though, Religion has nothing to do with freemasonry, nor does worship or anything of any specific doctrine. The only thing that is required is belief in a Supreme Being. The definition of which is left up to you and will not be questioned nor challenged.