So, even if it seemed a little abrupt and presumptuous, Hermione asked anyway.
Thanos fell silent for a moment, seemingly weighing his words-or perhaps he had never explained this to an outsider before.
"Gamora," he began slowly, his voice low. "When she was young, her homeworld was on the brink of collapse from depleted resources. Its civilization could no longer sustain itself. I took her away and wiped out half her people."
"Afterward, she saw with her own eyes how greatly life improved for the half who remained. The planet flourished again, becoming a paradise."
"So she understands my intentions. She knows that sacrificing some so the rest can live better is the only truth that will allow the universe to endure. Even now, she only opposes me because she is softhearted. She cannot accept that I must be the one to carry out this great plan."
"As for Nebula..." A trace of contempt entered Thanos's voice. "She is merely an augmented soldier who craves battle and slaughter. Her mind holds nothing but power and conquest. She cannot begin to understand the great balance I seek, much less make sacrifices for it. Her only value is as Gamora's sparring partner, honing her skills and making her stronger."
His explanation gave Hermione food for thought.
She still found Thanos's chain of logic rather impressively flawed, but at least it was slightly easier to understand than a simple "a father's love is boundless and beyond reason."
Put plainly, Gamora had seen the "beautiful outcome" of his successful "plan," so Thanos believed she "understood" him but simply could not accept it emotionally. Nebula had never seen it and had a one-track mind, so naturally, he treated her as nothing more than a tool.
Beside them, Ebony Maw, Corvus Glaive, and Proxima Midnight all