I'm with Tesla on the importance of torquing connections. Too much is as bad as too little. Even if you've stopped short of physical damage to the lug, you may have reduced the cross section of the conductor or stressed the connector to the point where thermal cycling will finish it off.

The majority of installers do not get to see the results of their work several years down the line and have no reason to believe their installation technique is a problem.

A recent experiment/study showed that about 80% of electricians and non-electricians could not tighten a connection within +/- 20% of the required value when not using a torque wrench.

Few things are harder to put up with than the annoyance of a good example.