If it really came down to the famine, I'd ask why isn't this mentality seen in Bangladesh, who also lost around 5% of it's population to famine in the 20th century? They're some of the kindest, most welcoming people I've been around in the face of a poverty that China no longer knows.
So I'm having a hard time believing that TFA isn't completely off on this one, as I'd expect a society that had 2000 years of contact with Buddhism to have absorbed at least a little of the Buddha's teachings on karuna. Especially one whose main school was that of Mahayana and it's ideal of the Bodhisattva.