Actually casinos already included their rules regarding with this in their terms and conditions and the mistake at the same time is on the player because we cannot deny the fact that most of the gamblers did not read the terms and conditions and also the Faqs regarding with the deposit, rewards, withdrawals and etc. as long as they get caught with the bonuses and see this could be good source of profit to them while playing gambling, and they will seek only these once they didn't receive the reward or they have trouble with their funds.
I interpret a casino with many betting requirements as a casino that wants to take the player's money but in a very subtle way and that cannot be seen as something bad, but rather as taking the money with some diplomacy, for those are the bonuses and the requirements are so high, personally when I see a casino with more than 2x I don't play and honestly I don't go back to that casino anymore, when we enter a normal casino that isn't online they don't give those options, you play with the money you bring it and that's it, it depends on the player if he multiplies it or loses everything, I don't play with casinos like that because the experiences I have are not good.