organic dirt, is the most complex form of nutirents you can provide the plant. while plant scientist are good, many believe that nobody is 100% on how or what makes plnts preform in their stages and while nutrient companies make better and better products, there are some missing micro nutrients, or even some other missing ingriedient due to nutrient uptake or some other proccess that takes place in an organic living environment. either way, this added complexity offers the opportunity to provide a complete (or the most comlete) feeding and growing environment. that is the most logical reason that has been explained to me why organic dirt may offer a different finished product vs. inorganic (which hydro has to be, as far as i know).
good luck with your endeavors