Because they're shipped over pre-assembled by the container ship load and cheap I imagine.
The Chinese cabinets I got from KZ were assembled in the San Jose warehouse. Probably came over flat packed on the boat. No issues with fit and finish. A blemished trim piece could be easily exchanged.
The Diamond cabinets from Lowe's were preassembled out of state & trucked in huge boxes. Those were the ones with crooked doors and poorly attached hinges. The lazy susan had a wobble! :laughing
Bikeama: Gorgeous kitchen! May I ask what the cabinet and countertop portion of your remodel ran you?