Casinos will always do what is best for them at least they must profit from the process. Despite bonus been a way to foster interaction between a user and the casino it is primarily a way to generate extra income for the casino. With that I am okay but I am not comfortable with how difficult they make their wagering requirement to be. On a normal ground they are indirectly doing exactly the same thing gamblers will do if they continue with the none deposit bonus system. Which is ripping the other party.
Bonuses are a kind of advertising, they can't take them away and among other things they can't not use them, otherwise no one would have, as it were, the incentive to use a new casino. It's right what they do, otherwise no one would try anything else. It's pure competition