I was hearing a mix of higher population density, worse hygiene, expectations of containment, different culture/government, skepticism of Chinese media honesty,

I was hearing a mix of higher population density, worse hygiene, expectations of containment, different culture/government, skepticism of Chinese media honesty, and (perhaps most importantly) downplaying by WHO and other experts. Italy was the nail in the coffin for those... optimistic expectations. Except among the lunatic fringe.