You being in the role and expertise that you are - excluding Operation Aurora for now because you seem to have a certain characterization of it - you know that China and the US hack each other for strategic purposes and that when China hacks the US it is not about dissidents.
We can't predict an alternate history here whether China would have gone after Google for other reasons. What we do know is that China went after the intelligence system linked up to GMail and used it for counter-espionage purposes. One Google personal relations spokesperson did say they suspected China of using the system to collect information of terrorists and dissidents as well.
Attributing motive of course changes the narrative. Making it sound like China wanted to hack Google for the sole purpose of getting to dissidents makes it sound all spooky and evil. The reporting that has China hacking Google to track down terrorists and dissidents usually 'forgets' to mention the counter-espionage link at all or that the database they accessed was for law enforcement or that they gained access to Google's systems exclusively through this system; so I tend to believe the reporting and sources that include more, rather than less, information.
There's purpose behind casting doubt on the intentions of China and the context of the compromise: this is known as spin. Spin is important - for PR and for propaganda - but if you want people to have a real conversation you've got to do what you can to minimize it.