User blog comment:Deafro/Theory on Dust Manufacturing/@comment-4773581-20140112153919/@comment-4773581-20140112175033

But do you really think they'd even be able to test such a dangerous method? Nobody would ever volunteer to test it, so they'd never get past the theoretical stage, and lightning/electric dust would forever remain a mystery. Your alternative method also relies heavily on modern science, which probably wasn't around back when they started with dust. Hell, the people of Remnant could still not know that method, assuming they simply adapted dust as a replacement of a lot of what we have.

And for dust to do what you are suggesting, it would have to reject all forms of energy, not just the energy it has been absorbing, so as to prevent the cross-contamination that your proposed theory is centered around. Which would, in effect, render them completely useless. Rejecting all forms of energy means nothing would trigger it, making them nothing more than decorative gems with exceedingly and needlessly complicated refinement processes.

And this still ignores the lack of explanation as to how the discovery of your proposed jumbled mess of relatively low amounts of various energies, which may or may not conflict with one another, managed to turn the war against the Grimm from the Grimm having a decisive upper hand to both sides reaching a relative stalemate. And keep in mind that, in regards to that point in time, humanity's existence (and assumedly the existence of the faunus, too) was described as "brief" in the opening narration of the series, meaning that much of the science, technology, and reasoning that you rely on would likely not have been available at the time.