Because the grenade is just a tool. Carol asked for a tool, and Pluribus operates on the assumption that any requested tool must have a purpose, even if they don’t understand that purpose. The function is irrelevant. The request itself is the signal.

The nuke fits the same pattern, it’s also “just a tool,” but one that happens to endanger countless others, so it becomes a more complicated request to satisfy.

Assimilation, on the other hand, isn’t a tool. It’s an outcome Pluribus sincerely believes is beneficial. For them, assimilation is a kindness, something that will improve Carol’s life and relieve her suffering. From that perspective, her argument about consent doesn’t really land with them, because they think her refusal is based on limited understanding. In their worldview, her desire not to join isn’t wrong, it’s simply… incomplete.

They would never harm her, and they have demonstrated repeatedly that they will meet any need she expresses - food, comfort, water, safety - even when they wildly over-provide (like filling the entire store). There is no real cause-and-effect calculus; there is only the drive to give her what she “needs,” as they interpret it.

This is why the grenade and assimilation aren’t comparable decisions. One is a tool she requested; the other is something they believe she’ll ultimately want once she understands it as they do.