User blog comment:Ironreaper/Problems with the Catalyst/@comment-4614261-20120411172636

There's also the point that the Catalyst makes about Geth hostility to organics, but in both Mass Effect 1 and 3, those hostilities are only because of Reapers rewriting the Geth AI to become hostile to organics. Legion confirms that Geth normally do not hold any hostility towards organics, not even the Quarians, and only fight in self defense. So in a way, the Catalyst and the Reapers were the cause of the problem they were trying to fix.