There are various types of retorts: i) the brain is also doing gradient descent; ii) what the brain does does not matter (if you can fake intelligence you have intellegence) iii) the pace is now so fast that has not happened in decades will happen in the next five years etc.
None of them is remotely convincing. I would really start getting worried if indeed some of the AI fanboys had a convincing argument. But we are where we are.
Somehow this whole episode will be just another turn of the screw in adopting algorithms in societal information processing. This in itself is fascinating and dangerous enough.