> Whether or not China will clone an app is immaterial to question of whether all companies will fold to Chinese government pressure.
It is very material though. If your business is not special/unique in some important way, then you don't have a lot of bargaining power when the CCP officials come to negotiate the terms. Then your choices boil down to -- accept whatever is offered or exit completely. While some exited completely, I very much doubt they did so on ethical grounds, as you seem to be implying. Rather, the terms were unsatisfiable.
Trying to get some sort of an acceptable to you deal is the only thing that makes sense from a business perspective. The alternative is losing access the world's biggest market and watching the state prop up a powerful new competitor that may well compete outside the borders of China too.
If you want American companies to be able to resist Chinese govt pressure, then you need to have significant intervention from the US government and hope that they will be able to broker some sort of a deal. Failing that, it's a joke to think that any company has any actual bargaining power in a negotiation with the Chinese govt.