Fine tuning: a discussion for the rest of us mortals

I never really did get this argument either...If the point of it all truly is life on earth, then why are there literally billions of other stars out there (except for our sun)? Vast ammounts of cold uninhabitable space? Etc. Seems like pretty poor "fine tuning" to me.If the Universe was fine-tuned for life I'd expect it to be full of it, not a smidge from being completely empty.
It's sort of like if someone brought you a new design for a cup and told you it was fine tuned to hold water. Then you look at the cup, and it's 10^50 cubic meters large, but can only hold a millilitre of water due to design issues. I'm pretty sure your conclusion would be that the cup designer is either joking or an idiot.

I'll concede that there might be life that we haven't yet observed, but it isn't really relevant to the point I was trying to make.
Without the observation of a Universe teeming (sp?) with life, the conclusion of fine-tuning for life is not warrented, and sort of ridiculous.