"When a nurse is fired, we're deprived of even the meager entertainment of knowing what exactly she did to deserve it, and a creepy but brief dream sequence offers an all-too-short reprieve."

Not sure how you could fault in the dream sequence as it was most beautifully shot. Perhaps you missed the subtle inference to what would later come. It seemed pretty clear to me and the audience what the maid did to get fired. Perhaps you missed it as you were too busy finding ways to nitpick a film that is, as you put it, "universally greeted with adoration." I suppose it's true what they say: a true cynic can find fault in any work of art.