Probably a smart move at the time, to drive a further wedge between the Chinese and the Soviets, since the Soviets were the greater threat and we needed to isolate them as much as possible.
The mistake was continuing to play patty cake with the Chinese once the Soviets were no longer much of a threat.
The Nixon China strategy was an effective one. The whole trade debacle we have been dealing with in recent decades evolved long after Nixon had left the scene.