I'm suffering

The rise of overly dark Magical Girl shows, which contain suffering for no other purpose than to display said suffering, largely stems from a complete misunderstanding of what Madoka was, and what made it great.

Madoka spends two and a half episodes setting up a happy, cheerful, Magical Girl show, and then spends eight and a half episodes rejecting that premise, showing that hope only leads to despair, that a wish will lead to a curse, that things cannot fundamentally improve, and that trying to make things better will only bring suffering upon yourself and others. This is what derivative "tragical girl" shows were about; the suffering of young women for its own sake, as if that was the point of Madoka, as if the suffering was the entire point.

The last episode, however, has Madoka herself rejecting the show's entire premise. She's told hope leads to despair, and exclaims "If someone says it's wrong to have hope, I will tell them they're wrong every single time.". She's told that the very foundation of the universe leads to suffering being inherent, constant, and that the only thing one can do is to endure said suffering as long as one can bear, before falling to despair and inflicting the suffering one has experienced unto others; she's told that any wish will become a curse, yet ends the show saying "All those Magical Girls who held onto their hopes and fought against witches, I don't want to see them cry—I want them to stay smiling until the end. If any rule or law stands in my way, I will destroy it. I will rewrite it. That is my wish, that is my prayer.""

Walpurgisnacht had been set up as the most terrible witch to ever exist up until that point, and the viewer had been led to believe they'd fight to the death against it, and inevitably lose—as a Magical Girl seemingly always does in the Madoka universe. Madoka does not fight her, Madoka shows compassion, simply stating "It's okay. It's okay now, you don't have to hate anyone anymore, you don't have to curse anyone anymore. I'll go back, before you took that form, and shoulder that burden for you". There was no fight, and Madoka simply took on her despair, as she took on everyone else's, allowing them to once again have hope.