Sounds like elitist bullshit to me....
I am one year into organic/living soil.
Not having done hydro, but having done salts then organic, the main difference I am noticing is that I am more easily able to keep plants perfectly healthy until they are ready to harvest. A perfectly tuned hydro would probably do the same, but one hiccup and your playing catch-up and watching leaves get crispy and ugly. Those leaves cannot possibly do the whole photosynthesis thing to it's fullest potential.
Purely anecdotal, but I am thinking the general potency is not effected. I think the THC, CBD or whatever major/primary canabinoids the plant is supposed to have are pretty much set in the bean. I think the individual grow is what's gonna bring that to it's full potential but I get just as high initially from ugly weed as pretty weed.
If you believe in the elusive entourage effect, then the terps matter. A plant that is perfectly healthy and photosynthesizing to the max until the natural senescence slows it down and the trichs are ready will have a better aroma than one you can wet-trim by brushing off the crispies. I've had both
Last bit of anecdotal I can check up on and report back. I ran a bean, a clone, then the clone of the clone. Same plant, three different levels of aroma, with the last one having an entirely new 'nuance' to the smell. From the same bean. After all are cured I can do a side-by-side and get a pretty good idea what I will choose to believe. Without some stoner college kid getting a masters thesis grant for research and lots of testing being done, it's all bro-science.