Fairy tales need to be a bit grimm (pun intended). They are supposed to teach about hardship and the difference between good and evil. You can only show the contrast if you actually have some evil to talk about.

A child dying in the flames she sparked by playing with a bunch of matches while she was home alone. The cats were trying to warn her, now they can only watch from afar as the child and house burn.

A homeless child having a final hallucination while watching (again) a bunch of matches burn while freezing to death outside. Another child dying from hunger because he refuses to eat what his parents are putting on the table. Yes, not the most uplifting stories, but where I come from, everyone knows these stories, and almost everyone knows them since they are about 5.