I don't think this is the reason. We let it slide over the last 10 years when every hack involving a Chinese IP address in any way was attributed to the Chinese

I don't think this is the reason. We let it slide over the last 10 years when every hack involving a Chinese IP address in any way was attributed to the Chinese government. Media reporting around cybersecurity doesn't tend to acknowledge that people other than the security services have computers in Russia and China. It became a meme among hacking victims to blame intelligence agencies, probably because it looks substantially less bad than getting owned by 15-year-olds. We let it pass without comment in dozens of cases before this one.