China wants you down right away and never issues a pilot discretion clearance. Descend at 1000' fpm and if they want more they will tell you. The reason they usually want at least 2000' fpm is to get you out of their airspace and into the next lower approach control airspace in other words they are passing the buck to get rid of you ASAP. I also generally climb at 250 knots until 6000 meters FL 197 so yo can get into the higher controller airspace and then you seem to get more favorable clearances.