Actually that's what some companies in the ASIC supply chain have done when the first bitcoin ASICs came out (2014ish I think?). That's probably because of the kinds of people in those companies, and the kinds of markets those companies operate in, i.e. solely in the bitcoin mining market. Nvidia and AMD mainly sell their GPUs for various other use cases other than mining, and the mining uses are quite recent. Nvidia is also known for building different products for different market segments, and they do have dedicated GPUs made for mining. I.e. in 2018 they forbode machine learning uses in datacenters of their consumer hardware in their EULAs, to push people to their professional hardware instead. https://www.datacenterdynamics.com/en/news/nvidia-updates-ge...