"Cinderella" seethes with a kind of sarcastic anger, a bitterness about people who get something for nothing. It's what everyone wants—to win the lottery, to marry a rich guy/girl, to never have to worry about money again. Cinderella is blessed with one good fortune after another, aided, of course, by her magical tree and bird. That sounds like a pretty sweet set-up. Still, the most biting examples of the speaker's annoyance towards Cinderella stories come at the beginning, with the short little examples of people who have stumbled into their wealth through some circumstance just barely under their control. What the poem wants to tell us is that our notions of luck and fortune are misguided. Even having everything we want does not guarantee that we'll be happy, or even really alive. How are those scratch-off tickets looking now?
Put that rabbit's foot in the trash, folks. The poem's strongest point is that all the fortune in the world will not give you a good life.
Talk about bitter! The tone of the poem demonstrates a low-level contempt, or bitterness, toward all of the characters in the poem who benefit from any kind of luck.