I don't think it's even an explanation. An explanation of how babies are made doesn't begin after conception.
The "big bang" theory looks more like an explanation of the universe's development, not of its origin. I may be wrong, but I believe the general theory behind the development of planets and stars long preceded the big bang theory.
I'm sure that the theory details are immensely fascinating to study, but from a layman's perspective, the actual "bang" is no more significant to a full explanation of the universe's origin than cell division is significant to an explanation of a baby's origin.
I think it's a misrepresentation to say that I'm asking for something else, a "cause", if I want to know what preceded either that first cell division or the actual bang.
Peoples' naturally curiosity is what drives us to investigate and reason through the universe. And the inductive part of that reasoning is probably driven by a natural "dissatisfaction" with the unexplained. Some put more faith in God to fill the void, and some put more faith in man's ability to reason since it has explained so much that was unknown for so long. But it still appears that the beginning of the universe is so completely unexplained and cosmologists are so completely without a clue, that God is as good of an explanation as any. And I say that as an atheist ;^)
I think this ambiguity is a place that evolutionists and creationists can come together. After all, what difference should it make to either if God set the world in motion through the big bang 15 billion years ago. If we simply respect each other's faith in the unknown, all we're disagreeing on is the method of creation/evolution. And as time passes, the evidence and clear thinking may put that question to rest.