@guy betsy,
Interesting.
Being a passenger, i would agree and that i'd love for CX to understand passenger (with preference for direct and in one sense to get the free stopover) insist on the HKG-ORD next day.
In fairness to CX, and if they can find an option, i think the logic they have is that by having the passenger fly at other option (LAX/SFO/NYC), they decrease the total flight time. The overnight stay does increase the overall flight time.
IMHO, I think the LAX/SFO or even a EWR option may come as a hassle to the passenger as now it becomes something like HKG-LAX-ORD-MDT or worst something like HKG-LAX-DFW-ORD-MDT and i'm not mistaken, this may potentially increase the cost of the flight.
(While still ORD? as some regional flights still comes out of ORD than anywhere else.)
Now knowing CX, they probably thought the hotel stay would cost more.