I imagine there was a conversation something like this....
NVidia engineers: "miners don't need most of the stuff in these chips, we can manufacture one for miners without the unnecessary stuff cheaper, or even use reject bin parts to bring the cost down and increase sales and availability, win win"
NVidia accounts: "hey that's great, but if we also cripple the normal one, we can sell it for the same price or even more expensive, win win WIN"