You are not wrong however it is undeniable that some casinos have some wagering requirements that are very hard to achieve and this is what bothers some gamblers, as only by gambling nonstop they will be able to fulfill those requirements.
It is because of this that is important to read the requirements of each bonus before we accept it, as in my experience trying to fulfill those requirements takes a great deal of the fun I get from gambling, since instead of gambling just for the fun of it I will begin to gamble with the idea of fulfilling those requirements no matter what.
Completing the wagering requirements for a bonus can only be fun if you are playing a slot game that is constantly paying you well and your balance isn't draining up which way you can continue to play until the requirement is met, otherwise, if you keep losing by getting dead spins every time, you won't have much fun in fulfilling the requirements.
Personally, I'm not a fan of bonuses that have very high wagering requirements since it becomes very time-consuming and tiring trying to fulfill those requirements and sometimes you even lose your deposited funds only in the middle of completing the requirements.