God was throwing a curve ball when creating the Big Bang
Its the only explanation I can come up with for the spinning motion...
Just kidding, although I think the motion created by the big bang had to have something to do with the creation of spin during the consolidation of the stars, planets, galexies, etc...
There must be ripples (High points & Low points such as gravity or energy gradients) which set it all in motion.
I know little of all the physics involved, but its a great question.