Hindsight. At the time, nobody had travel restrictions. Were they all influenced by China? No, with the then current information travel or trade restrictions didn’t make sense.
This is the same lazy argument as with the 737 MAX - why wasn’t it immediately grounded? Well, you can’t just shut down the world at any sign of trouble. You have to make an informed judgement call with the information you have at the time. Sometimes, ex post, it will turn out to have been the wrong call. Doesn’t mean you need to revise or impugn the decision procedure.
This is the same lazy argument as with the 737 MAX - why wasn’t it immediately grounded? Well, you can’t just shut down the world at any sign of trouble. You have to make an informed judgement call with the information you have at the time. Sometimes, ex post, it will turn out to have been the wrong call. Doesn’t mean you need to revise or impugn the decision procedure.