Simply because the lack of Chinese bag holders to buy and hold our bags.
every day 2k of bitcoin created, who is going to buy them?
huge amount of bitcoins gonna be sold by Chinese, no one can buy them and hold the price above $2k, in fact, not even $1k.
When BTCChina shuts down there will still be other exchanges like OKcoin if i'm not mistaken. BTCChina does have quite a big market share in China but it's definitely not the only way that the Chinese can accumulate their BTC.
I agree that it's probably a bull trap right now and most likely price is going down to around $2.5k after this. But i don't think it's going to be sub-$2k any time soon, let alone the sub-$1k prediction that you are making.
I would say anyone wanting to enter the market, at least do so without going "all-in".