We don't know whether APPL shareholders would be interested in Apple exiting Mainland China. Apple needs to act in the shareholders' interest, but I don't think it necessarily has to act to maximize profits. Also, Apple could have a shareholder vote on the matter; perhaps the majority of shareholders prefer that Apple maintain its reputation for privacy over its profits. Perhaps exiting Mainland China would not affect Apple's profits much--given that I couldn't walk into the Beijing Apple Store without being accosted by sellers of presumably illegally imported iPhones from Hong Kong to avoid the 25% luxury tax, perhaps Apple's China profits would simply morph into Apple's HK or Singapore profits. Perhaps Apple leaving China would make them that much more desirable--the ultimate luxury item is the one you can't get.

The pricing between HK and Beijing is much reduced these days, definitely a lot more than it was when the first Apple stores opened (you can compare prices between apple.com/cn and apple.com/hk if you don't believe me). The days of the yellow cows are mostly over, and have been on decline for a few years now (they no longer hang out at the Sanlitun Apple store as of 2016, for example).

I don't think ANY company can afford to leave China these days. Google only got away with it because they weren't making much on search in China.