Vulnerability factors for China:
1) Almost a fifth of the world's population lives there. The more people a nation has, the more chance of having the first human carrier for any given communicable illness.
2) Nearly all of them are carnivorous. This is primarily relevant in conjunction with the next few items, but it is the primary reason that India, which has nearly as high a population, is much less often the source of pandemics.
3) Relatively heavy animal agricultural sector, both in terms of percentage and absolute numbers. Novel communicable illnesses most often start because of live animals transmitting to humans, so anywhere with large portions of the population raising farm animals is going to have increased risk. Rich nations are not immune to animal-to-human illnesses, as Britain providing the world with BSE in the mid-1990s shows. But it is live
animals that tend to provide the communicable ones. The USA and India both have weaker animal agriculture sectors than China, despite both being substantial - the former because it has lots of prime land for growing grain, the latter because a lot of its people are vegetarian.
4) The sheer size of the domestic market means there is incentive for some of these to be huge, many to be family farms aimed at serving all/part of a village, and every size in between. This makes it hard for a best-practise consensus that is feasible for all sizes. Many other countries either tend towards small-scale or large-scale, and therefore get to be firmer in what they demand for agricultural hygeine. The USA and EU avoid this problem by tailoring requirements to big operations (since that's where most American and European people get their food from). India's is less-enforced, but what is enforced tends to be things that every farmer in that area could reasonably do.
5) Uneven distribution of information about best farming practises, including best hygeine practises. So some people simply do not know what options there are to do better in the field of not accidentally killing one's customers. This, at least, is changing due to China having the world's greatest penetration of smartphones, but information literacy skills haven't caught up, so not everyone is using it optimally for professional purposes such as farm hygeine.
6) Lots of poverty in the countryside, making it more difficult to access and afford medical treatment - and ruling out self-isolation for many due to the need for income to meet survival bills. In COVID-19's case, it also means people are less likely to be protected against animal bites (e.g. by going to market by car) - a bat bite just before or during travel to market is believed to be the original infection point for the first case. This is the first risk factor China shares with the USA - except that the USA's heavy use of cars means bats and parasites are unlikely to be the animals giving new illnesses to Americans! For the USA, it would mostly affect ability for any initial cases to get treatment or testing.
7) Much greater emphasis on community than other parts of the world (partly because that's the nature of impoverished rural villages, partly because of historic cultural factors) and more multi-generational families, leading to people being unable to self-isolate even if they can afford it (because other people are depending on them to do things, and they are themselves dependent on other people for other things). The USA and Europe are far more individualistic, which means that fewer people are in the initial circle of infection. This may also be a factor in why Italy has had a greater rate of fatalities from COVID-19 than other European nations - it tends to have multi-generational families under the same roof too.
Hub-based movements. There are two sets of hub-based movements in China: people in rural villages going to a local town/city (and just to make it more vulnerable, a fair number take their live animals with them in both directions, because not all villages have an abbatoir) and people going from local town/city to regional hub cities. The regional hub cities are also "local cities" for their immediate rural area. This means getting from "one village affected" to "thousands affected" is a one-step or two-step process. Most places that have more even distribution of wealth than China have more distributed patterns of travel too. So people don't gather so much in a "hub", rather people go to many different places, but not all at the same time. This slows the movement of the illness and (usually) reduces the number of people who get infected.
9) Wealth in the cities. So people there can access medical care, self-isolation and raise the alarm. This contrasts poorer nations, where the illness could go all the way through a city without being recognised as being novel (unless there happens to be a unique symptom or something like that).
10) Good testing facilities in cities, so cases tend to be found as soon as the cities get it.
11) Lots of regional flights, that vast numbers (in absolute terms) of Chinese people use on a regular basis. So it gets across the nation quickly, no matter how fast the reaction is.
12) Massive international hub to everywhere in the world. So once the illness hits Beijing, Shanghai, Hong Kong or a few other key cities, international spread is inevitable. Thanks to 9), there's a good chance any given bug will. It also means there's a chance nations that are too poor to identify a bug in their location may find it goes to China, is identified there, and is then blamed on the Chinese even though someone else brought it in.
13) Different approach to PR. This is the one thing for which blame can sensibly be put onto people, specifically the leadership. A propensity to downplay bad news is not wise in a crisis, as people then tend to downplay the need to take precautions. This was also a problem in Italy for COVID-19, and appears to be a problem in the UK and USA also. However, none of these three countries has anything like the same powerful causation chain as China. They all have breaks in the chain, so not only are they less likely to generate a new communicable illness, there's more chance of it getting stopped before it properly gets started.
I am waiting to see if my board games club runs on Friday night. My guess is that either way, we will not be playing Pandemic as it is likely to be too close to home...