The implication isn't that being Chinese makes one likely to be a hacker. It's the other way around. It's that being a hacker makes it unusually likely that you're Chinese (or Russian). Similarly, being a Nigerian doesn't make you an email scammer, but being an email scammer makes you unusually likely to be Nigerian. Being a drug lord makes you unusually likely to be Mexican.

These are archetypes, i.e. popularly associated examples of particular actions. But I'm not sure if they're full-blown stereotypes, where they get over-applied to members of that group. People don't believe that all Chinese and Russians are hackers, that all Nigerians are email scammers, that all Mexicans are drug overlords, etc.

Stereotypes tend to be more insidious. Many people (in America) do believe that Blacks and Mexicans are criminals, that Chinese are great at math, etc., to the degree that it changes how they actually treat people. So I think these are much worse and shouldn't be equated.

That said, despite the above analysis, I can see how being Chinese you would still cringe when you see the phrase "Chinese hacker" being used casually. I'm an ethnic minority and have felt similarly in similar situations.