It is hard for the Chinese carriers to get pilots to work and stay for any length of time because it is so far away.
No, it is hard for them to get people to stay because they tend to treat people like ****.
Broken promises about T&Cs, contract changes when they feel like it with no consultation and no recourse, fines for foqa events and late flights, ****ty 2 star hotels on layovers, just to name a few.
I'm not saying Deer Air is like this, but there are many carriers out there who are.