Because that's actually how it IS in China.

China is a giant corrupt honeycomb. There are blurred lines between corporation/government. Corporations are often a face for government interests. It's totally corrupt, and everybody knows that the face of an organization is not the actual motives behind the organization.

A single Chinese clan will control multiple branches of government and multiple corporations. They all seem separate, but they have the same interests and work together.

It makes sense for the Chinese to assume that the US is similar. That there is some corrupt connection behind the faces of separate entities, just like in China.

In point of fact I think this kind of hacking attempt is a kind of ham-handed attempt to control what cannot be controlled. The Chinese are pissed, and so someone put some money and time toward attacking the NYT. And not doing a very good job, either.

The US, by contrast, has more direct ways to express its displeasure.

Maybe but more likely one faction thinks another has leaked info and wants to get evidence. The power struggles over succession to the leadership are very serious. Indeed the whole business of staying in power is serious eg current case of poisoning.

And the only people who can do this are the government and corporations? Surely not all traffic leaving China is accounted for by the government.