I might be wrong, but I thought that Kriemhild Gretchen was powerful enough to kill all life in the solar system within minutes,
Three days and only the planet, but close enough.
so its creation would be a one time payoff of grief.
No. I'm saying that based on what we know, Kyuubey should be able to continue collecting from Gretchen post-witchout, from a distance, forever.
A lot of grief, naturally, but (barring a Madokami style wish where she specifically absorbed the grief of every witch past, present, and future) unlikely to be equal to the total grief production of humanity over the course of tens of thousands of years.
Every time Homura goes back, she gets the Karmic potential of the previous entire Universe added to her. She should be more than equal to a hundred Universes worth of witches.
It doesn't matter that most girls don't realize the enmity or don't act on it: as Homura displays in Rebellion, it only takes one girl to evict or enslave or destroy the entire incubator race for all time. Kyuubey is messing about with entities capable of reality warping wishes and magic, so he really ought to be more careful about ensuring our goodwill, even if it does mean that the grief harvest would be less efficient. This is one area where the analogy of farming breaks down: humans have real leverage to use against the incubators if it comes to a fight (or a negotiation).
Okay, here is something you have to understand. Incubators do not feel fear. They do not feel threatened. They have
never felt these things. They have evolved to be completely without a risk-assessment response. They have no experience with things that have actually threatened them and feeling risk aversion has had no benefit to them on an evolutionary scale as nothing from their home planet even approaches being a threat to them. The concept that they should be careful is completely foreign to their mindset. They have no fight or flight response.
That is why they act like this.
Do they do geography differently where you're from? My lessons were all about volcanoes and how rivers form and weathering on cliff faces.
Two different sections of the same subject in the syllabus I studied. Political borders, capitals, town development, population demographics, imports and exports etc. were all included as were said things on river and cliff formation.
Becoming a witch is a psyche destroying experience that compounds all the failures you've ever had upon your mind all at the same time. It is not like just being really sad or in stasis. It's analogous to volunteering to have a mental breakdown and then being used as a depository for despair for a year, once every 15 years. You don't just walk off a major mental breakdown. That shit sticks with you. It would be torture to ask someone to do that.
To put it another way, it is implied that a witch would immediately suicide out of despair if it was capable of doing so. A witch is feeling horrific suicidal depression on top of unbearable agony. To the point that they kill the humans around them in an attempt to gain temporary relief.
