"Huge puzzle for physics: how did the universe tune itself into this very delicate balance? Some people prefer the multiverse. This is called by some the end of physics. Basically, what they're saying is some things we'll never explain, so let's just postulate that there are an infinite number of possible universes and we happen to be in the one that came out like this...There's not much more to it than that."
Personally, I think there's a much more compelling explanation for why our extraordinary universe appears to be deliberately fine-tuned - it is.
'[God's] invisible attributes, namely, his eternal power and divine nature, have been clearly perceived ever since the creation of the world, in the things that have been made. So [those who deny him] are without excuse' (The Bible, Romans 1:20).