If we were trying to describe stochastic gradient descent, this would be relevant, but we're talking about backprop (which does often use just a batch, but that

If we were trying to describe stochastic gradient descent, this would be relevant, but we're talking about backprop (which does often use just a batch, but that's not inherent). And there is nothing about backprop that makes the kangaroo more blind than in any other form of gradient-based optimisation.