I think that was a wives tale started back in the day. Some old schooler please correct me if i'm wrong, but they used to believe that hanging the entire plant upside down would cause the THC to migrate into the buds. Science has proven however that it does not.

It does seem like it would be a royal pain in the ass to manicure an entire plant, let alone a harvest, after it had dried. Everything is sticking out nice and pretty showing you exactly where to cut at harvest day, the 2 just seem to go so well together. Plus I would think you would lose less resin glands while the plant is wet, vs handling all the dry nugs. All of the leaves that were sticking out would shrivel and stick to the buds, and if you get rid of em, I would imagine they would pull more crystals with them.