I think about a gazillion people identified exactly this type of situation as a problem, and we’ve had plenty of other outbreaks. It is completely unsurprising. The UK has done a lot of modelling and prepping for such an event, as I’m sure have other governments, but that doesn’t give you magic powers when it happens.
It's also worth bearing in mind that there's precisely one country which could possibly have done what he suggested and stopped this by preventing the spillover in the first place - China - and, well, good luck with that.
I think the problem is that the virus is so mild. You can't spot a lot of cases, so e.g. someone gets on a plane and is not showing symptoms and a few days later in Italy they get sick or infect others without realising they're ill.
