[galaxyLogic]

It's not only that we can't know what the optimal choice is. We also can't know how far the benefits of our choice are from the benefits of the optimal choice.

And what would be the expense of figureing out what the optimal choice is.

I got into this way of thinking this morning starting with what is the definition of "Technical Debt". I would say it is the cost of moving from the current implementation to the optimal implementation.

But we don't know what would the optimal implementation. That means we can't even begin to estimate how much it would cost to refactor the current implementation into the optimal implementation.

Therefore I conclude that "Technical Debt" is consultant-speak. Something you can sell without clearly explaining what you are selling.