The_KFD_Case wrote...
The Geth are likely quite aware of the difference between "shutting down" and permanently "killing" something. However, if they are no longer in a position to turn themselves back on and have to trust another species to do this then it's not difficult to comprehend why the Geth may perceive it to amount to the same thing for them in practical terms. There is no guarantee that the species that shut them down will reactivate them after all, and once that is done the Geth would be unable to further impact the situation.
Yea, I recognize that the Geth were retaliating, at least in part, for immediate self-defense. But I sincerely DOUBT that the amount of carnage was just the Geth stopping the Quarian standing next to them from pressing a button on their omnitool. Likely, it seems, the attacked the Quarians in general, without distinguishing innocents or foes. That would not be surprising, considering Geth are not particularly intelligent, or at least because they lack several mental functions that organics have, like empathy and fear.
But the Quarians did not think they were killing Geth. They thought they were shutting them down and possible just editing the code. If you shut down your computer that doesn't mean you can't turn it back on, after changing the motherboard or whatever.