Why would someone dismiss intelligent design?

Big Bang? sounds more like pr0n than a theory, how did this "explosion" happen, it is impossible for something become of nothing. The chances of big bang/evolution are the same as swiping a magnet over your hard drive and booting into a full working os, preinstalled with 100s of popular games, impossible. explain to me step-by-step how this CRAP happened. I believe there was NEVER nothingness in this dimension, for god was ALWAYS here.