In theory, most of the connections have recommended torque values for the screws. You can see this on breakers, etc. Not so much on the whip cords. You almost never see a torque wrench in a residential installation, but you will in commercial settings.

If you over-tighten a screw, you end up stretching the threads on the screw or on the connector. The end result is that you will make it looser. Even if you stopped "before" you stripped the screw, you still might have excessive force being applied to the threads. Subsequent vibration, thermal cycles, etc. might eventually loosen the connection.

I spoke with a few physicists about this topic last year, and none could think of a reference, but they all agreed that putting too much torque or too little torque both cause the resistance at the connection to be increased compared to the resistance with the specified torque. It is not just a matter of the mechanical aspects of the connection.