Agree to what you have been said. But this promotion is for VIP's so what they want to lure are those gambler who usually spend a lot of money on other casino. They have done the first round of this promotion and provably it didn't end up well for them since they encounter lots of abuse at that time. So right now they put those requirements to determine their target also to avoid encounter issue regarding those people who usually take advantage on promotions which doesn't have much requirements asked.
But since they offer generous cashback I guess that's good enough for VIP transferee to try and earn some benefits of this program. They have lots of promotions done intended for all and I guess those promotions could attract small players, but for now they target those big fish to transfer in their casino.