I'd say there needs to be a point to defoliating, or you're just hurting your plant. Normally you trim to manage the lighting and/or ventilation for humidity control. If you don't have plants crowding each other, then your plant can receive light through the sides. Leaves there will help. More leaves also help buffer stress on the plant and control the local climate once you build a canopy. On the other hand, allowing the plant to bud all the way down will result in lower-quality buds down low, and maybe (I'm not 100% convinced, but I'm a beginner) results in taking away something from the top buds. Personally, I leave them more leaves than most, and I use the resulting lower buds for concentrates.