The difference is, it is likely not a problem for whales to lose big time since they're rich, unlike to some average gamblers (who keep on playing to win) because it can really hurt their financial status.
Nevertheless its really wise to not rely on gambling as a money making activity because its risky.
Whales have their own way of gambling and they can risk big amounts also and they play as leisure activity but we should enjoy our way of gambling playing always in limits because we can't compete with them at any level so it's better to be your own in this game.
Some whales rely too much on their gambling profit, they earn big but they lose big as well. We can’t just compare every whales since they have their own purpose to gamble and different goal most probably. Whales might not interested anymore with the bonuses but still Rollbit is very generous and they have promotions for VIPs and most probably they are also participating on that. If you are not that big time gambler, just enjoy the game.
Even if those bonuses are nothing to whales, it still important for a casino to have a continuous promotion on their platform. It provides more entertainment to its users to keep playing on their platform. It's one of the sign I look for in considering a good gambling website.
Casino events are also one of the things that gamblers enjoy because most of them are known to be competitive and winning on those highly boost their confidence in gambling.