No problem. Yeah, they can see it in-person quite easily. I know exactly where those machines are, and they get checked constantly. I guess they feel it’s easier to ID advantage players through continual winning sessions on games like that than nab them one by one.
Maybe they also don’t want to run the risk of pinching some grandma who is harmlessly clicking around on the buttons. After all, security and slot attendants may not be well-versed enough to differentiate someone like that from a true advantage player. The numbers the player card spits out will tell them all they need to know.