It's kinda bad business to fully pull out of a giant market, with a massive customer base, because of a major boom cycle in your product.
Do you know how difficult it is for a company to expand their business to new markets? Do you know difficult it is the build up a customer base in a market?
This isn't just doing addition and subtraction on n GPUs/year. This is business. We wouldn't have so many businessmen if business was that simple.
it's worse than just that. in this case it creates an even stronger incentive for a domestic chinese competitor to rise up and as soon as a chinese competitor can offer a similar product to what nvidia is offering, then nvidia's clock is already ticking. its probably too late already