If it was completely inappropriate for kids, the movie should have been rated NC17 not R. If the movie was misrated than why blame the parents for taking their kids to see it? The whole point of the R rating was to give parents the option of deciding whether or not it was good for their children. If the movie was so completely wrong for kids, the the NC17 rating should have been handed out. I can’t blame a parent for exercising an option that was given to them.
Because it's not the movie company's responsibility to watch out for her kid - it's her's. And anyone who's watched more than a dozen R rated movies knows you shouldn't take a 5 year old kid to one. Saying "Well, since they don't prohibit my kid then it must be OK for him to see" is a total cop-out to avoid responsibility.