Even with a parent, the draw is just too attractive for kids. I tried desperately to explain to my kid that these games were rigged against him. He didn't believe me, didn't care, told me all his friends said they won, got angry at me for trying to take away his fun... He gets it now at 15, but at 6 there was no convincing him.
At least the carnival midway games these days have mostly switched from rigged against the kids to everybody wins a crappy prize. But these arcade game types are straight up gambling for children.