Maybe its just my experience but as a kid my little sister and I would laugh hilariously at drunk/drugged people in cartoons. And we are five years apart. I don't even remember my parents having a huge drug talk with us, the movies pretty much explained it. If you drink or take drugs you will act like an idiot and that just wasn't attractive to us.
Land Before Time, Brave Little Toaster, Watership Down, those were scary movies! I remember crying a little during those movies but it wasn't too bad. Though for halloween my friends were all suggesting scary movies to watch and when I suggested Brave Little Toaster no one wanted to go through that again! I just watched the Last Unicorn for the first time last week, now that was freaking dark! (Also very lovely and its something I want to see again)
I think that parents should vet out movies before their kids see them, especially if they have very sensitive kids. My parents have friends that see every kids movie in theaters twice, once without their kids and then once with them. But it seems like a very vocal minority is going to make parents afraid of letting their kids experience anything.