[0xCMP]

"Well the stadium/store/restaurant/security-area has cameras and we saw you pressing the button [at all]. Care to explain that?"

(Also: why would they press the button? bad reviews being given)

"We see that, while your over all ratio of good to bad isn't horrible, you have quite a bit more bad than usual and more votes than usual without the sales we'd expect."

[hnal943]

By the time you add the costs to administer these buttons which includes detecting fraud, reviewing security footage, and contacting the store, the value proposition of these buttons evaporates. It's no longer a cheap source of customer feedback.

[0xCMP]

They could notice weird things like these and sounds like they have done things like lookup the camera footage before to identify an issue.