Wasn't that a common way of thinking by Americans?
Not by a long shot. We definitely have our fair share of weirdos over here, but making that type of assumption is not normal by any definition.
And when i made that comment, I was mainly referring to mangaka and putting children in their manga. There are so many manga where children are put into questionable situations that it has to be a country level problem for it to show up so many times. I don't know if they just have more weirdos than us or if the weirdness is more concentrated, but it's very concerning for so many manga to sexualise children so openly and not at least receive heavy backlash for it.