What do annihilationalists make of Matthew 26:24 (and Mark 14:21)?

In Matthew 26:24 Jesus says > The Son of man goeth as it is written of him: but woe unto that man by whom the Son of man is betrayed! it had been good for that man if he had not been born. Also in Mark 14:21 it is repeated > The Son of man indeed goeth, as it is written of him: but woe to that man by whom the Son of man is betrayed! good were it for that man if he had never been born. These statements seem to indicate that, for at least one man, there is something worse than the non-existence of remaining unborn. What do those who hold to a doctrine of ultimate annihilation for the un-redeemed make of these verses: In what way is eventual non-existence worse than mere non-existence?