Sword,
Because he makes up things that do not exist, hence are false by default and then compares them with aspects of religious belief, e.g. the likely existence of God. There is no common frame of reference unless the starting assumption is that all religious belief is made up, therefore also false by default.
Try really, really hard to focus here. Really hard...
Whether leprechauns, "God", "X", pixies or anything else is made up
is utterly irrelevant to the maxim. Really - made-upness has nothing to do with it: zip; nada; zilch; bugger all. My god, even Vlad was edging toward that realisation yesterday albeit that he then fell off the cliff by thinking that it would have to apply to all arguments rather than to just any of them.
What's being addressed here isn't the
object of the belief ("God", leprechauns, whatever) at all. What
is being addressed though is the
argument(s) used to arrive at that object. Thus for example the NPF is still a very bad argument whether it's used to demonstrate "God", leprechauns or anything else.
To put it another way, even if I was a dyed-in-the wool hard core fundie Christian who thought that the belief "God" wasn't ridiculous at all, I'd
still have no choice but to recognise that the NPF is a hopeless way to demonstrate it - especially when I realised that it worked equally for any other conjecture.
That's the point of the maxim. Surely even you can grasp this now can't you?
Can't you?