>>281992544
Self-actualization is a core theme of Sayaka and Kyouko's arc. Sayaka doesn't just crash out randomly, this entire meguca fiasco hinges on how she sees herself. Mami even explains things in very simple words for her "are you making this wish for Kyosuke because you want to, or do you want him to be thankful for it", but Sayaka still has to go for it. Mami dying only makes Sayaka more motivated: she WANTS to be the heroine of justice she saw Mami as (that's the image Mami gave off and she only broke the facade with Madoka).

So Sayaka goes with the wish and the world breaks her apart slowly, by showing her she's not the person she wanted to be. She can't truly act in complete altruism and self-sacrifice, which is a pretty important theme in Madoka. The reason she witches out is because she loses her sense of self, and her innocence.

Meanwhile Kyouko takes a bit of a different path, she starts with the same good intentions but unlike Sayaka she adapts by changing on the spot, and condemns her former self instead of clinging onto it like Sayaka did. But in the end she never TRULY forgot these ideals and they influenced her actions beneath the facade she projected.

I see Kyouko's sacrifice as a moment of warmth and regain of innocence. A stronger one, that is more rooted in reality than the images Sayaka and Kyouko tried to project beforehand. Maybe being a perfect heroine of justice isn't realistic but finding empathy for someone (even a stranger/enemy like Sayaka) and trying to help them is possible and just as meaningful. The world is cruel and cold but it's possible to capture a sense of meaning and human connection in spite of it. And even in the face of death it's possible to find dignity and peace. There's a sense of everlasting beauty and intimacy in that exit.