Since people have a craving for the supernatural, why do people deny miracles?
I would want to ask the questioner a question- Do all people have a craving for the supernatural? I don’t personally think this is true. There is something in the arguments used by C.S. Lewis, as well as Augustine, about being purposed for God, and without having God there is something missing. Moreover, the Apostle Paul wrote in both Romans 1 and 2 that all people have an awareness of natural things being derived from God as well as the conscience (think awareness of right and wrong) as pointing to God.
But, I would not want to personally affirm that all people have a craving for the supernatural. What if someone does not have a craving for the supernatural? Would that mean that God does not exist or that people do not need God? Nope. God would still exist and they would still need Him. As far as miracles are concerned, I think it wise of us to remember that miracles are not a regular occurrence. Some people go around saying that they are, but that is not really the Christian position. The Christian position is that God sometimes does a miracle, and the more public ones typically have larger purpose in the history of humanity. The Resurrection is a case in point. This miracle was a form of proof as to who Jesus was, as well as a down payment for who we would become.