I am guessing you are talking about an amusement park in Japan. Well, I am guessing that beside basic law and regulations, each amusement park come up with its own procedures and most likely those policies differ from ride.

All I can guess is that if they go through items in riders pocket and sorting through what is allowed and what is not allowed, then that likely will slow down the line. May be the line move faster if they simply say everything out from the pocket.

About single riders alone, well, if you feel that strongly about it then you should complain to the amusement park.

Well, least enjoy Fuji Q, it is the first amusement park in Japan to install those extreme ride roller coaster.