A witch didn't do things because they seemed a good idea at the time! That was practically cackling. You had to deal every day with people who were foolish and lazy and untruthful and downright unpleasant, and you could certainly end up thinking that the world would be considerably improved if you gave them a slap. But you didn't because, as Miss Tick had once explained: a) it would make the world a better place for only a very short time; b) it would then make the world a slightly worse place; and c) you're not supposed to be as stupid as they are.