"Common usage" says that wrought iron is the crap they sell at Sears. "Common usage" says there are male and female cows. There are hundreds of words in common usage that are just plain wrong.

I can certainly agree with that point, not all common usage of words are correct. Many incorrect usages do replace correct usages over time ("lock and load" might sound cooler than "load and lock", but its pretty difficult in practice). In this, though, I would say that even in relevant metalworking industries and experts, "heat treatment" would be considered to be an intentional process with a defined purpose, not an accidental one.

I believe a process is a process regardless of "intent" or "desire" or "benefit". Gold can be refined and concentrated in nature, but it's still refined. The process of distillation is still distillation whether deliberate or accidental. If I accidentally knock a hot piece of A-2 in my slack tub, it will probably become hard and crack. No intent, desire or benefit, but to me it's still been "heat treated". Sometimes when people are forging a tool, they are warned not to quench it lest it become hard or "heat treated". So if they lay it on a brick to cool don't they display "intent and "desire" for a certain "benefit"? Wouldn't that be deliberate "heat treating"?

How can a process be defined by the emotion we are feeling at the time we do it (intent, desire)?

One of the most widely accepted definitions of magick is "To focus your will and intent in order to produce a desired effect".
No wonder many folks believe heat treating is pure magic.

One of the most widely accepted definitions of magick is "To focus your will and intent in order to produce a desired effect".
No wonder many folks believe heat treating is pure magic.

I don't know about that, but it is the "secret" to forge welding.