I am aware of Hawking radiation, but it does not properly explain how a black hole would evaporate after reaching Planck mass, only that it would reduce in mass until it was unable to attract anything. (There is a very reasonable proposal that black holes thus reduced would actually be stable weakly interacting massive particles, and would form much, if not all, of dark matter.) Also, if a black hole would be created at CERN, it would be fed by a very energetic proton beam, potentially much faster than it could possibly evaporate by hawking radiation.

That cosmic rays also potentially produce black holes is also not a good argument against their production, but only against the danger they pose. A black hole with the mass of a few grams has a very tiny cross-section, and since momentum is conserved, would probably be moving very close to the speed of light. Should a cosmic ray hit earth and produce one, it would likely pass right trough earth without hitting any significant amount of matter or slowing down. This is of course also true for any black hole created at CERN -- The protons traversing the rings are doing so at roughly 0.99999999c. Should a black hole be created, it would leave the solar system in a rather short time, at least from it's perspective.