There's a very simple fix that they could make, which would all but kill mining without meaningfully impacting gamers. Mining rigs generally try to run as many GPUs off a single motherboard as possible. That's detectable. They also often run those GPUs off single PCIe lanes. That's also detectable, even if the mining rig tries to hide the other GPUs via IOMMU or other methods.
If either is detected, then the card goes into a "mining sabotage" mode, errors are randomly introduced, the clock rate declines exponentially with total power on hours, random lockups occur, and just generally, make the card look broken.
Gamers aren't going to connect cards to single PCIe lanes (you need adapters, and gaming performance would be terrible), and they aren't going to put 4 to 16 cards in a single system, so they'd be completely unaffected.