To me, the mere act of calling the fundamental structure of the universe "fine-tuned" sounds fallacious; it seems to assume that there's any sort of tuning involved. It seems equally valid to assume that a random process exists that happened to give rise to our universe. We don't know how long it took for the universe to begin, or whether it's the only one, or even if the question makes sense.<p>Lots of religious people like to use fine tuning to imply that there is a designing intent behind the universe, usually completely ignoring the fact that only a vanishingly small part of it can harbor life at all. Are we certain that there aren't parameters which would produce even more life? What about universes with an entirely different structure?<p>I also personally object to the notion that it's somehow acceptable to assume a creator has to exist, but not acceptable to assume that the universe has to exist; the latter assumption is much less far-fetched.
Maybe there's a multiverse--an infinite series of universes, containing all possibilities of existence, some with similar, slightly different constants, others completely unrecognizable as a universe at all. And life exists because we're in this one.