When North Star came out was lot complaints why have to be weighed, it's limits are also for possible for rescue. If breaks and you are stuck the equipment used to lift and lower you is reason for max weight of one person. To OP almost all Water Parks ans Amusement Parks have Height, age and weight limits, Disney, Universal, Six Flags, ect. Even NCL and Carnival have limits on their's and I'm sure Royal didn't pick a random number out of thin air without reason