Kids in mind
When I first heard about this site, I was expecting it to be the kind of site where they're passing some kind of moral judgement against every movie. This was not the case.
Instead they give each movie a score out of ten for each of three categories: one for sex and nudity, one for violence, and one for coarse language. So, essentially the three things that might make a parent reluctant to show a movie to their child.
They'll also give a list of every incident of these things happening on screen in fairly dry language. Consider this from their page on Kill Bill Volume One: "A woman bites a man's lip (or tongue, it's not clear) and pulls, he screams and falls onto the floor motionless, his face and chest are covered with blood, and she is covered with blood. We hear panting and moaning, pan onto a woman with a very bloody and bruised face and see her shot in the head. A woman cuts a woman's arm off: blood sprays and pours and the woman flails and screams..."
This is the kind of language used when they describe the violence they see on screen. It's dry, and it doesn't pass judgement on whether or not these things should be shown to children. It's left up to the parents to decide whether or not it's okay to show their kids this stuff.
At the end of these sometimes monotonous lists of every single violent, sexual, or foul mouthed incident, they'll provide a list of discussion topics related to the movie (presumably so a parent can talk to their kids about what they've just seen), and the general message of the movie. The discussion topic list for Kill Bill Volume One reads, "Respect, murder, mercy, revenge, changing one's life, death of parents."
So while this site could have quite easily have become just a shoehorn for someone to moralise about what a child should and shouldn't see, they seem to have largely avoided this. Instead, they've taken a much more common sense approach to what they're doing: they advise parents that a movie might be violent, sexual, and profane, but they also give a list of discussion topics so that parents can have the opportunity to use any movie as a learning tool to discuss serious issues with their kids.