That's really not true at all. The grade of materials makes all the difference in the output of the product... so it's another layer, on TOP of your refining process, that should make a difference.
If I take the time to gather grade A pure iron as opposed to grade C pure iron, there should be a difference in the output of the product I'm making. If it's a gun, maybe more durability. If it's a radar dish, perhaps it's higher density.
But beyond quality/grade, I'd like to see materials have properties as well - for example, weight, conductivity, strength, etc And different combinations of those materials could make them the right choice for project A, and a different combination of those material attributes could make a better choice for project B.