What you say has merit. But let me throw out a scenario...

What you say has merit.

But let me throw out a scenario unrelated to mining.
My brother used to be a bank manager. And I remember him saying to me before I bought my house that I needed to assume interest rates were 3% higher than the current rate when evaluating what I can afford to spend.

Now, commodity prices have taken a hit in the last year. We know that.
When you start building a plant you don't click your fingers and it's built, it takes two years.

Financiers need to use historical figures.
So should you. And that's not even taking into account the expected demand increase for the commodity.