Mentioning the word whip gives people creeps. Especially in connection with animals. A whip is viewed as something to punish slaves with during colonial times, and as something which can only creat pain.
But the use of the whip can, as with so much else be operated out of different ways and power, with anything from light tushes on the skin to sound cracks that doesnt even touch the animals. As for the sake of elephants, even if it is used with power in a special situation, it doesnt inflict as much abuse of the elephant skin as does the hook, and it reduced the elephants feeling of bodily punishment from the trainer, as compared with the hook.