Not all countries are like China.
Other places could have a helpful bureaucracy, or one that ignores the laws, or accepts bribes.
How does this matter when the country is known ahead of time, and the relevant laws, the details, etc., are all widely known to be nowhere near identical?
It’s not like someone could accidentally board a flight to China and clear immigration by happenstance, or without being informed that things may be very different from their home country.
They were probably optimistic, incorrectly. It's easy to think everything will work when you have a written guarantee from the government, and have never personally experienced a dysfunctional, authoritarian bureaucracy.
An invitation from a local official can not be a written guarantee of something beyond them?
It’s not even a guarantee of getting the relevant visa in time, that’s true for every big country I know of.