Some people enjoy a challenge. God, in his infinite wisdom, has designed some fruit for those people as well.
Actually, that’s a pretty good answer.
catsix, though you know I agree with your underlying idea here, I just want to note that someone may be along soon enough to believe that, yes, they were designed that way. I was told as a little Hebrew boy in Sunday school that the fruit and nuts with harder shells were “closer to God” because they were protected from the material world.
Damn it, I’m just helping the enemy, aren’t I?