Animatronics aren't common in America; I've gone my whole life without seeing one in person. They're even less common these days because they've fallen out of favor for cheaper options.
However, I think it's the uncommon nature of them they makes the memory of them more powerful. Many people have vague and fleeting memories of having seen them maybe once or twice in their childhood, maybe at Chuck E. Cheese or Disney or something. And they are uncanny. I think FNAF taps into a very specific vague and fleeting memory of creepiness that many Americans have. It's kinda neat though.
