Yeah this basically the same with most of the exchanges. Most of the "liquidity" is actually provided by the exchange themselves. Even a reputable exchange like Kraken, most of the order book is the owners of Kraken. Why do you think they needed $10m (or whatever the amount was) in VC funding?
With bitfinex i suspect they are actively trading themselves against the users. They are not very good at that but then again the liquidity is so bad and fees high that on balance they are probably making some good cash.
However its not just finex I suspect all the btc exchanges are doing the same things.
For what its worth bitfinex are i believe Italian guys, even if they are in hong kong i'd still trust them more than any of the China exchanges. Take the most dodgy investment (bitcoin), one of the most suspicious industries (forex trading) and put it in the world's most dodgy country (china)..
Lets be honest Im not racist but its well known that chinese are known for their scams, ponzi schemes, shadow banking, copying western products, etc. . The history of china is full of civil wars and scams its one of the most unruly countries in the world (after maybe Russia). Every Chinese dynasty seems to only last about 50 years before there is a civil war and a new emperor arrives. Result is all chinese spend there time fighting the whole time. They are very unruly people.
So yeah I wouldnt go near these chinese exchanges probably even bitfinex is more reliable than either okcoin or huobi.