Well, they do have their sinister side. Their rigid commitment to 'family values', mainly- for one thing, they've been instrumental in marginalising animation as a serious artistic medium, since many people automatically assume anything animated is for kids- the Japanese would beg to differ. Plus, most of Disney's stories are taken from other sources, and they're not shy about editing and altering the stories to suit them. This is bad enough when it's a traditional tale like Beauty and the Beast, but look at Pochahontas- that's the life of a real historical figure they were screwing with. (Also, this is why the sequel movies always suck so much... they keep using someone else's characters and setting, but abandon any pretense of faithfulness to the original story.)
Oh, and they're ultimately all about reaffirming the values of the white male middle-class establishment in one form or another- even the stories that were originally from completely different parts of the world. Maybe your teacher has been reading the same books I have...
