There are users that also seeks for the bonuses that the casino can give back. As far as I see it, some reputable casinos tend to decrease their rewards overtime, that's I think the reason why some players are willing to play on newly created casinos. Well there are many new popping platforms that seems good so it might be worth a shot.
There are several reasons players try out new casinos because the referral bonus is high but there is no guarantee the reputation and safety of the new casino will be worth using, they want bonuses from referral links and are looking for various ways to gather more gamblers who will join that link. So for anyone please be careful promoting a new casino referral link without doing research will be bad for referral users.