[snowman]

So what about the professor and his zillions of students( mostly mechanics who do real day to day work) who all tend to agree with him?

The heat does also a lot of good on metal corrosion, and breaking any bond it may have made. The reason it breaks this bond is the slight difference in coefficients of expansion of the metals.

Ask almost any mechanic. Add a bunch of heat from a torch and it will almost invaribly make the thing come apart, easily.