Bored... so...
The most common argument of defolihaters (wearing that label with pride) is "photosynthesis" or "solar panels" which yes kind of says enough already but it always leads to the same (ignorant) counter argument of the inner part of the plant needing light.
Photosynthesis is however just one function of leaves...
Take a bottle of mineral nutrients, let the water evaporate, and behold the small amount, the low weight of nutrients. Obviously that small amount alone isn't going to be enough to account for the weight of all those heavy buds. The light provides energy, which is stored as sugar (which is burned for energy, and transported throughout the plant..."this is a whole plant phenomena - transport of photosynthate from leaf to root", see phloem sap translocation, eg
http://www.uic.edu/classes/bios/bios100/lecturesf04am/lect19.htm ). The water we dry out the buds obviously doesn't account for all the bud either.
So where does the bud come from, what is it made of and how do plants get all that material... Hint: For photosynthesis open stomata are essential. While calyxes are through evolution modified leaves to protect the seed, and on some species bracts contain a small amount of stomata, they are located at the underside of the leaf, which obvious incase of a cannabis calyx would be useless. In addition to "gas exchange", plants transpire water through their leaves. Transpiration is a primary process for the plant as a whole (water+nutrient uptake) but also again for photosynthesis. Now imagine a LED grower (lower temp means less water potential in the air means less transpiration), growing organics, who defoliates, and flushes. The closest thing you can get to "flushing a plant" is increasing transpiration, which requires leaves... the more leaves you have, the more water you can "flush" through your plants.
"It's the good advice that you just didn't take"