I will prove to you that God exists

[Alan V]

As you say, it's hard not to feel sorry when apologists devote so much effort to defending irrational arguments. Sadly, if you start with a belief that you're not prepared to abandon, this is bound to happen. I mean if my position ever required I contradict known fact, or a dictionary definition to defend it, I'd have to discard that belief. There is no belief I wouldn't abandon if the objective evidence made it untenable. 

Evolutionary psychology tells us that people defend their ideas for social reasons, but it still comes down to a sunk-cost fallacy if those ideas don't hold up to critical scrutiny.

However, I do appreciate the argument that scientists need to explain the biofriendly characteristics of our universe if there is no multiverse. I give Drew that much credit.

The argument just doesn't have that much to do with atheists per se. We have abandoned the God-concept for a number of other reasons, and God is an uneconomical hypothesis to explain either the big bang or the specific characteristics of the universe which actually resulted from it.