I don't attack atheism, I don't see the reason why you feel that attacking Christianity is so important, but whatever floats your boat.
Well, I think he can attack it for the sake of the attack... I don't believe anybody's viewpoints ought to be exempt from criticism, and I don't think people should ever "just agree to disagree".
That said, maybe he has a good reason for attacking Christianity. Maybe he thinks it's dangerous to somebody, such as society as a whole, or religious individuals, and that therefore it behooves right-thinking people to put a stop to it.
I completely agree, the only thing is, we've been over the same ideas at least four or five times now, without getting anywhere, so we know it's not going to go anywhere... so what is the point?
If at first you don't succeed...
Perhaps one of these times something productive will come out.
With supernaturalism, the miracle of evolution is replaced by a Creationist magic trick, the annals of reality, with its confounding mystery and unfathomable beauty is warped into a human likeness, the mechanics of causality and mystified into a cloud of spiritual uncertainty, the practice of science is chained by unmovable assumptions, and the desire to stir a false boredom pushes away the truth - and real "magic" of the universe.
In any case, the supernatural can only be the unexplained natural.
'Every great movement must experience three stages: ridicule, discussion, adoption.' - John Stuart Mill