Because those price-sensitive buyers (PC gamers) are far more likely to be loyal customers down the road than crypto miners, who will immediately stop buying GPUs as soon as mining stops being profitable again.

Nvidia wants to give PC gamers a reason to stay on "Team Green" by making it easier for them to get a card at a reasonable price during this perfect storm of limited silicon availability and insane crypto mining demand.

I actually think that this particular move is more about rate limiting purchases intended for crypto mining than it is about putting miners in a different market segment.