This flight is mainly for ORD connections, and so the flight timings are based around that, which is the reason why there are bad connections from HKG.

CX has timed this flight to arrive in ORD so that multiple connections can then be made, with good departure/arrival times.

Not many people will want to arrive into ORD in the evening and connect at that time even if there are connections. People would probably still use LAX/SFO.

It has been hinted that a second flight will be added to ORD in the future, I guess we will see, depending on how this flight goes. It is likely that if a second flight were added it would be timed for good HKG connections.