Maybe the Chinese are peculiar, or the price is just too high compared to other high end handsets. And the cheap Chinese iPhone knock-offs with as many as 3 SIM card slots are widely available and very popular. The resemble the genuine iPhone till you get to the fake iPhone OS X and realise it is just too fake.
And we have a new iPhone 4G (or iPhone LTE) coming soon, may be the Chinese who work in the sweatshops in Downtown Shanghai that make the iPhone has told the local populace to just wait for the new iPhone.