And in less than half the words I would have used to say it :P
One of the main points of the detractors, of course, is that admiring the girls "in that way" while watching them twerk dance is in itself an act of psychic abuse. You are "perverting" them with your mind by feeling that way and thinking such thoughts about them. This is not the way adults are supposed to think when viewing an underaged girl, and doing anything remotely sexually expressive or looking attractive etc. is not something kids are supposed to do. You are, in effect, violating their "innocence." They will insist kids would never want to express themselves in any way remotely sexual unless they were abused, emotionally disturbed, or simply imitating what they see adults doing on social media to try and act more "grown up" instead of "just being a kid" and skipping rope (like Amy did at the end of the film) or drawing rainbows, baking mini-cakes on toy stoves, etc., like girls are supposed to do.
One of the most amusing things about the detractors is how so many of them (including Ted Cruz himself) are boasting that they didn't watch the film and never would, but are going entirely by hearsay and Netflix's initial trailer because it would make them ill, or they worry the FBI would start investigating them, etc. It's become a full-blown moral panic within the context of a larger moral panic.