Yes you do. Uncle ben and your butt buddy in the magic schoolbus fan club are so misinformed when it comes to defoliation, no wonder all you do is bash it, it's beyond your old school growing rules of thumb and actually based on science! Time to get educated in recent scientific information ( well, 1970's ). If you cared to listen to people more often rather than think your so awesome, you might improve your growing techniques a little. Whats the point of thinking your the best and never improving? I have not heard a reasonable explanation out of you yet for why your topping method works better than defoliation. Let me explain for you Uncle ben a little bit on how it works.
You ever hear of Absisic Acid?It is a chemical compound that regulates stem and bud growth and bud and seed dormancy. Absisic acid is primarily produced in the leaves of the plant inside the chloroplast and it controls hormonal concentration in the apical meristem that alters the last set of leaves in a stem into a leaf covered protection system for the flowers. Even though Absisic Acid is chemical compound it still functions like a hormone. When it degrades or catobolizes (i think thats how you spell it) it affects the metabolic rates effecting cell growth and the production of other hormones in the plant. When a plant is in its seedling stage, the Absisic Acid levels are at its highest, then as the plant matures, the Absisic acid levels begin to decline. Once the plant produces offshoots with fully functioning leaves, the Absisic Acid levels in the plant begin to increase, that slows down growth in more mature areas of the plant.
EDIT: I think by removing the leaves UB where the Absisic Acid is produced, you are regulating hormonal concentrations in the plant. Or is this too hard for you to understand?