Me too. I've noticed that most of the photos seem to be of plants that haven't been trained and are growing straight upwards, an inherently flawed strategy for anyone using artificial lighting. I can see how defoliation would drastically increase the yield from the lower part of the plant in that case. I'm not convinced that someone growing under a scrog or LST or other training method would see much benefit.
Actually it is the SCROG that benefits most. Those who are still going vertical will sooner or later learn to limit vertical growth and eventually train to limit it further, open up the center and SCROG for support. Thus SCROG is an eventual outgrowth of defoliation or vice-versa.