Technically it's feasible though. They could "gimp" the cards just enough to deter miners from purchasing them. Along with some slightly shady business antics, both AMD and Nvidia could profit even more by doing so.
Nvidia and AMD are the only players in the desktop discrete GPU market, they could come to an agreement to market their geforce and RX cards as being "gaming optimised" or some bs along those lines. Those cards would only have driver optimisations for games and nothing else, no professional apps, no more openCL or CUDA optimisation. BIOS would be completely locked down and unflashable, even for non reference cards. Maybe even no overclocking/undervolting without setting off a hardware fuse and rendering the warranty invalid.
Meanwhile, they include those missing features in their new workstation cards which have a much higher profit margin for them. The desperate miners and those who require the optimised compute functionality will still buy them, but it will largely kill the mining industry due to the huge startup costs compared to before.
It would be a very "evil" move but it would deter miners from purchasing gaming cards as the workstation cards would have a great deal better hashrate and tweakability. Gamers would have to use locked down cards but it's still a better than the current situation where there are very few GPUs available. Maybe it's a tactic for Intel when they release their discrete GPUs, they have shown in the past that they are willing to use every trick in the book as long as it profits for them so I definitely wouldn't put it past them.