it's choosing the wrong class the gradient is guaranteed to be nonzero the gradient of the cross entropy with respect to the logits approaches 1 as the probability assigned to the correct class approach is zero so we can never get in a situation where the classifier is unable to learn due to a lack of gradient either it has gradient and it's making a mistake or it lacks gradient and it's perfect so the discriminator has this particular property but unfortunately if we negate the discriminators cost then the generator has the opposite of that